fetchmail(category13-admin-isp-software.html) - phpMan

fetchmail(1)              fetchmail reference manual              fetchmail(1)

NAME
       fetchmail - fetch mail from a POP, IMAP, ETRN, or ODMR-capable server

SYNOPSIS
       fetchmail [option...] [mailserver...]
       fetchmailconf

DESCRIPTION
       fetchmail  is  a mail-retrieval and forwarding utility; it fetches mail
       from  remote  mailservers  and  forwards  it  to  your  local  (client)
       machine's  delivery  system.   You  can  then handle the retrieved mail
       using normal mail user agents such as mutt(1), elm(1) or Mail(1).   The
       fetchmail utility can be run in a daemon mode to repeatedly poll one or
       more systems at a specified interval.
       The fetchmail program can gather mail from servers  supporting  any  of
       the  common  mail-retrieval protocols: POP2 (legacy, to be removed from
       future release), POP3, IMAP2bis, IMAP4, and IMAP4rev1.  It can also use
       the ESMTP ETRN extension and ODMR.  (The RFCs describing all these pro-
       tocols are listed at the end of this manual page.)
       While fetchmail is primarily intended to be used over on-demand  TCP/IP
       links  (such  as  SLIP  or PPP connections), it may also be useful as a
       message transfer agent for sites which refuse for security  reasons  to
       permit (sender-initiated) SMTP transactions with sendmail.

   SUPPORT, TROUBLESHOOTING
       For troubleshooting, tracing and debugging, you need to increase fetch-
       mail's verbosity to actually see what happens. To do that,  please  run
       both  of  the  two  following commands, adding all of the options you'd
       normally use.

              env LC_ALL=C fetchmail -V -v --nodetach --nosyslog
              (This command line prints in English how  fetchmail  understands
              your configuration.)

              env LC_ALL=C fetchmail -vvv  --nodetach --nosyslog
              (This  command line actually runs fetchmail with verbose English
              output.)
       Also see item #G3 in fetchmail's FAQ <http://fetchmail.berlios.de/
       fetchmail-FAQ.html#G3>
       You  can  omit  the LC_ALL=C part above if you want output in the local
       language (if supported). However if you are posting to  mailing  lists,
       please  leave it in. The maintainers do not necessarily understand your
       language, please use English.


   CONCEPTS
       If fetchmail is used with a POP or an IMAP server (but not with ETRN or
       ODMR),  it has two fundamental modes of operation for each user account
       from which it retrieves mail: singledrop- and multidrop-mode.
       In singledrop-mode,
              fetchmail assumes that all messages in the user's account (mail-
              box)  are  intended for a single recipient.  The identity of the
              recipient will either default to the local user  currently  exe-
              cuting fetchmail, or will need to be explicitly specified in the
              configuration file.
              fetchmail uses singledrop-mode when the  fetchmailrc  configura-
              tion  contains  at  most a single local user specification for a
              given server account.
       In multidrop-mode,
              fetchmail assumes that the mail server account actually contains
              mail  intended  for  any number of different recipients.  There-
              fore, fetchmail must attempt  to  deduce  the  proper  "envelope
              recipient"  from the mail headers of each message.  In this mode
              of operation, fetchmail almost resembles a mail  transfer  agent
              (MTA).
              Note  that  neither the POP nor IMAP protocols were intended for
              use in this fashion, and hence envelope information is often not
              directly  available.   The ISP must stores the envelope informa-
              tion in some message header and. The ISP  must  also  store  one
              copy  of  the message per recipient. If either of the conditions
              is not fulfilled, this process is unreliable, because  fetchmail
              must then resort to guessing the true envelope recipient(s) of a
              message. This usually fails for mailing list messages and  Bcc:d
              mail, or mail for multiple recipients in your domain.
              fetchmail  uses  multidrop-mode  when  more  than one local user
              and/or a wildcard is specified for a particular  server  account
              in the configuration file.
       In ETRN and ODMR modes,
              these  considerations do not apply, as these protocols are based
              on SMTP, which provides explicit envelope recipient information.
              These protocols always support multiple recipients.
       As  each  message is retrieved, fetchmail normally delivers it via SMTP
       to port 25 on the machine it is running on (localhost), just as  though
       it  were being passed in over a normal TCP/IP link.  fetchmail provides
       the SMTP server with  an  envelope  recipient  derived  in  the  manner
       described  previously.   The  mail  will then be delivered according to
       your MTA's rules (the  Mail  Transfer  Agent  is  usually  sendmail(8),
       exim(8),  or  postfix(8)).   Invoking  your system's MDA (Mail Delivery
       Agent) is the duty of your MTA.  All  the  delivery-control  mechanisms
       (such as .forward files) normally available through your system MTA and
       local delivery agents will therefore be applied as usual.
       If your fetchmail  configuration  sets  a  local  MDA  (see  the  --mda
       option), it will be used directly instead of talking SMTP to port 25.
       If  the  program fetchmailconf is available, it will assist you in set-
       ting up and editing a fetchmailrc configuration.  It runs under  the  X
       window  system and requires that the language Python and the Tk toolkit
       (with Python bindings) be present on your system.   If  you  are  first
       setting  up  fetchmail for single-user mode, it is recommended that you
       use Novice mode.  Expert mode provides complete  control  of  fetchmail
       configuration,  including  the multidrop features.  In either case, the
       'Autoprobe' button will tell you the  most  capable  protocol  a  given
       mailserver  supports,  and  warn  you  of  potential problems with that
       server.

GENERAL OPERATION
       The behavior of fetchmail is controlled by command-line options  and  a
       run  control file, ~/.fetchmailrc, the syntax of which we describe in a
       later section (this file is  what  the  fetchmailconf  program  edits).
       Command-line options override ~/.fetchmailrc declarations.
       Each  server name that you specify following the options on the command
       line will be queried.  If you don't specify any servers on the  command
       line, each 'poll' entry in your ~/.fetchmailrc file will be queried.
       To facilitate the use of fetchmail in scripts and pipelines, it returns
       an appropriate exit code upon termination -- see EXIT CODES below.
       The following options modify the behavior of fetchmail.  It  is  seldom
       necessary  to specify any of these once you have a working .fetchmailrc
       file set up.
       Almost all options have a corresponding keyword which can  be  used  to
       declare them in a .fetchmailrc file.
       Some  special  options are not covered here, but are documented instead
       in sections on AUTHENTICATION and DAEMON MODE which follow.
   General Options
       -? | --help
              Displays option help.
       -V | --version
              Displays the version information for your copy of fetchmail.  No
              mail  fetch  is  performed.  Instead, for each server specified,
              all the option information that would be computed  if  fetchmail
              were connecting to that server is displayed.  Any non-printables
              in passwords or other string names are shown as  backslashed  C-
              like escape sequences.  This option is useful for verifying that
              your options are set the way you want them.
       -c | --check
              Return a status code to indicate whether there is mail  waiting,
              without  actually  fetching  or  deleting  mail  (see EXIT CODES
              below).  This option turns off daemon mode (in which it would be
              useless).   It doesn't play well with queries to multiple sites,
              and doesn't work with ETRN or ODMR.  It will return a false pos-
              itive  if you leave read but undeleted mail in your server mail-
              box and your fetch protocol can't tell kept  messages  from  new
              ones.   This  means  it will work with IMAP, not work with POP2,
              and may occasionally flake out under POP3.
       -s | --silent
              Silent mode.  Suppresses all progress/status messages  that  are
              normally  echoed to standard output during a fetch (but does not
              suppress actual error messages).  The --verbose option overrides
              this.
       -v | --verbose
              Verbose mode.  All control messages passed between fetchmail and
              the mailserver are echoed to stdout.  Overrides --silent.   Dou-
              bling this option (-v -v) causes extra diagnostic information to
              be printed.
       --nosoftbounce
              (since v6.3.10, Keyword: set no softbounce, since v6.3.10)
              Hard bounce mode. All permanent delivery errors  cause  messages
              to  be  deleted  from  the  upstream server, see "no softbounce"
              below.
       --softbounce
              (since v6.3.10, Keyword: set softbounce, since v6.3.10)
              Soft bounce mode. All permanent delivery errors  cause  messages
              to be left on the upstream server if the protocol supports that.
              Default to match historic fetchmail documentation, to be changed
              to hard bounce mode in the next fetchmail release.
   Disposal Options
       -a | --all | (since v6.3.3) --fetchall
              (Keyword: fetchall, since v3.0)
              Retrieve  both  old (seen) and new messages from the mailserver.
              The default is to fetch only messages the server has not  marked
              seen.   Under  POP3,  this  option  also  forces the use of RETR
              rather than TOP.  Note that POP2  retrieval  behaves  as  though
              --all  is always on (see RETRIEVAL FAILURE MODES below) and this
              option does not work with ETRN or ODMR.  While the -a and  --all
              command-line and fetchall rcfile options have been supported for
              a long time, the --fetchall command-line  option  was  added  in
              v6.3.3.
       -k | --keep
              (Keyword: keep)
              Keep  retrieved  messages  on  the remote mailserver.  Normally,
              messages are deleted from the folder  on  the  mailserver  after
              they  have  been  retrieved.   Specifying the keep option causes
              retrieved messages to remain in your folder on  the  mailserver.
              This  option does not work with ETRN or ODMR. If used with POP3,
              it is recommended to also specify the --uidl option or uidl key-
              word.
       -K | --nokeep
              (Keyword: nokeep)
              Delete  retrieved  messages  from  the  remote mailserver.  This
              option forces retrieved mail to be deleted.  It may be useful if
              you have specified a default of keep in your .fetchmailrc.  This
              option is forced on with ETRN and ODMR.
       -F | --flush
              (Keyword: flush)
              POP3/IMAP only.  This is a dangerous option and can  cause  mail
              loss  when  used improperly. It deletes old (seen) messages from
              the mailserver before retrieving new  messages.   Warning:  This
              can  cause  mail  loss if you check your mail with other clients
              than fetchmail, and cause fetchmail to delete a message  it  had
              never  fetched  before.  It can also cause mail loss if the mail
              server marks the message seen after retrieval  (IMAP2  servers).
              You  should  probably  not use this option in your configuration
              file. If you use it with POP3, you must use the  'uidl'  option.
              What  you  probably  want  is  the default setting: if you don't
              specify '-k', then fetchmail will automatically delete  messages
              after successful delivery.
       --limitflush
              POP3/IMAP  only, since version 6.3.0.  Delete oversized messages
              from the mailserver before retrieving  new  messages.  The  size
              limit  should  be  separately specified with the --limit option.
              This option does not work with ETRN or ODMR.
   Protocol and Query Options
       -p <proto> | --proto <proto> | --protocol <proto>
              (Keyword: proto[col])
              Specify the protocol to use when communicating with  the  remote
              mailserver.   If  no protocol is specified, the default is AUTO.
              proto may be one of the following:
              AUTO   Tries IMAP, POP3, and POP2 (skipping  any  of  these  for
                     which support has not been compiled in).
              POP2   Post Office Protocol 2 (legacy, to be removed from future
                     release)
              POP3   Post Office Protocol 3
              APOP   Use POP3 with old-fashioned MD5-challenge authentication.
                     Considered not resistant to man-in-the-middle attacks.
              RPOP   Use POP3 with RPOP authentication.
              KPOP   Use POP3 with Kerberos V4 authentication on port 1109.
              SDPS   Use POP3 with Demon Internet's SDPS extensions.
              IMAP   IMAP2bis,  IMAP4,  or  IMAP4rev1 (fetchmail automatically
                     detects their capabilities).
              ETRN   Use the ESMTP ETRN option.
              ODMR   Use the the On-Demand Mail Relay ESMTP profile.
       All these alternatives work in basically the  same  way  (communicating
       with standard server daemons to fetch mail already delivered to a mail-
       box on the server) except ETRN and ODMR.  The ETRN mode allows  you  to
       ask  a compliant ESMTP server (such as BSD sendmail at release 8.8.0 or
       higher) to immediately open a sender-SMTP  connection  to  your  client
       machine and begin forwarding any items addressed to your client machine
       in the server's queue of undelivered mail.   The ODMR mode requires  an
       ODMR-capable  server  and  works similarly to ETRN, except that it does
       not require the client machine to have a static DNS.
       -U | --uidl
              (Keyword: uidl)
              Force UIDL use (effective only with  POP3).   Force  client-side
              tracking  of  'newness'  of messages (UIDL stands for "unique ID
              listing" and is described in RFC1939).  Use with 'keep' to use a
              mailbox  as a baby news drop for a group of users. The fact that
              seen messages are skipped is logged,  unless  error  logging  is
              done  through  syslog  while  running in daemon mode.  Note that
              fetchmail may automatically  enable  this  option  depending  on
              upstream server capabilities.  Note also that this option may be
              removed and forced enabled in a future  fetchmail  version.  See
              also: --idfile.
       --idle (since 6.3.3)
              (Keyword: idle, since before 6.0.0)
              Enable IDLE use (effective only with IMAP). Note that this works
              with only one folder at a given time.   While  the  idle  rcfile
              keyword  had been supported for a long time, the --idle command-
              line option was added in version  6.3.3.  IDLE  use  means  that
              fetchmail  tells the IMAP server to send notice of new messages,
              so they can be retrieved sooner than would be possible with reg-
              ular polls.
       -P <portnumber> | --service <servicename>
              (Keyword: service) Since version 6.3.0.
              The service option permits you to specify a service name to con-
              nect to.  You can specify a decimal port number  here,  if  your
              services  database  lacks the required service-port assignments.
              See the FAQ item R12 and the --ssl  documentation  for  details.
              This replaces the older --port option.
       --port <portnumber>
              (Keyword: port)
              Obsolete  version of --service that does not take service names.
              Note: this option may be removed from a future version.
       --principal <principal>
              (Keyword: principal)
              The principal option permits you to specify a service  principal
              for  mutual  authentication.  This is applicable to POP3 or IMAP
              with Kerberos 4 authentication only.  It does not apply to  Ker-
              beros  5  or  GSSAPI.   This  option  may be removed in a future
              fetchmail version.
       -t <seconds> | --timeout <seconds>
              (Keyword: timeout)
              The timeout option allows you to set a server-nonresponse  time-
              out  in  seconds.  If a mailserver does not send a greeting mes-
              sage or respond to commands for the  given  number  of  seconds,
              fetchmail  will drop the connection to it.  Without such a time-
              out fetchmail might hang until the  TCP  connection  times  out,
              trying  to  fetch mail from a down host, which may be very long.
              This would be particularly annoying for a fetchmail  running  in
              the  background.   There is a default timeout which fetchmail -V
              will report.  If a given connection receives too  many  timeouts
              in succession, fetchmail will consider it wedged and stop retry-
              ing.  The calling user will be notified by email  if  this  hap-
              pens.
              Beginning with fetchmail 6.3.10, the SMTP client uses the recom-
              mended minimum timeouts from  RFC-5321  while  waiting  for  the
              SMTP/LMTP  server  it is talking to.  You can raise the timeouts
              even more, but you cannot shorten  them.  This  is  to  avoid  a
              painful  situation  where  fetchmail  has been configured with a
              short timeout (a minute or less), ships  a  long  message  (many
              MBytes)  to  the local MTA, which then takes longer than timeout
              to respond "OK", which it eventually will; that would  mean  the
              mail gets delivered properly, but fetchmail cannot notice it and
              will thus refetch this big message over and over again.
       --plugin <command>
              (Keyword: plugin)
              The plugin option allows you  to  use  an  external  program  to
              establish the TCP connection.  This is useful if you want to use
              ssh, or need some special firewalling setup.  The  program  will
              be  looked up in $PATH and can optionally be passed the hostname
              and port as arguments using "%h"  and  "%p"  respectively  (note
              that  the  interpolation  logic  is  rather primitive, and these
              tokens must be bounded by whitespace or beginning of  string  or
              end  of string).  Fetchmail will write to the plugin's stdin and
              read from the plugin's stdout.
       --plugout <command>
              (Keyword: plugout)
              Identical to the plugin option above, but this one is  used  for
              the SMTP connections.
       -r <name> | --folder <name>
              (Keyword: folder[s])
              Causes a specified non-default mail folder on the mailserver (or
              comma-separated list of folders) to be retrieved.  The syntax of
              the  folder name is server-dependent.  This option is not avail-
              able under POP3, ETRN, or ODMR.
       --tracepolls
              (Keyword: tracepolls)
              Tell fetchmail to poll trace information in  the  form  'polling
              account  %s'  and 'folder %s' to the Received line it generates,
              where the %s parts are replaced by the user's remote  name,  the
              poll  label,  and  the  folder  (mailbox)  where  available (the
              Received header also normally includes the server's true  name).
              This  can  be  used  to  facilitate  mail filtering based on the
              account it is being received from.  The  folder  information  is
              written only since version 6.3.4.
       --ssl  (Keyword: ssl)
              Causes  the  connection  to  the mail server to be encrypted via
              SSL, by negotiating SSL directly after  connecting  (SSL-wrapped
              mode).   It is highly recommended to use --sslcertck to validate
              the certificates  presented  by  the  server.   Please  see  the
              description  of --sslproto below!  More information is available
              in the README.SSL file that ships with fetchmail.
              Note that even if this option is omitted,  fetchmail  may  still
              negotiate  SSL  in-band  for  POP3  or IMAP, through the STLS or
              STARTTLS feature.  You can use the --sslproto option  to  modify
              that behavior.
              If no port is specified, the connection is attempted to the well
              known port of the SSL version of the  base  protocol.   This  is
              generally a different port than the port used by the base proto-
              col.  For IMAP, this is port 143 for the clear protocol and port
              993  for  the SSL secured protocol; for POP3, it is port 110 for
              the clear text and port 995 for the encrypted variant.
              If your system lacks the corresponding  entries  from  /etc/ser-
              vices,  see  the  --service  option and specify the numeric port
              number as given in the previous paragraph (unless your  ISP  had
              directed you to different ports, which is uncommon however).
       --sslcert <name>
              (Keyword: sslcert)
              For certificate-based client authentication.  Some SSL encrypted
              servers require client side keys and certificates for  authenti-
              cation.   In  most  cases, this is optional.  This specifies the
              location of the public key certificate to be  presented  to  the
              server  at  the  time the SSL session is established.  It is not
              required (but may be provided) if the server  does  not  require
              it.   It  may  be the same file as the private key (combined key
              and certificate file) but this  is  not  recommended.  Also  see
              --sslkey below.
              NOTE: If you use client authentication, the user name is fetched
              from the certificate's CommonName and  overrides  the  name  set
              with --user.
       --sslkey <name>
              (Keyword: sslkey)
              Specifies  the  file  name  of  the client side private SSL key.
              Some SSL encrypted servers require client side keys and certifi-
              cates  for  authentication.   In  most  cases, this is optional.
              This specifies the location of the  private  key  used  to  sign
              transactions  with  the  server  at  the time the SSL session is
              established.  It is not required (but may be  provided)  if  the
              server  does not require it. It may be the same file as the pub-
              lic key (combined key and certificate file) but this is not rec-
              ommended.
              If a password is required to unlock the key, it will be prompted
              for at the time just prior to establishing the  session  to  the
              server.  This can cause some complications in daemon mode.
              Also see --sslcert above.
       --sslproto <value>
              (Keyword: sslproto)
              This option has a dual use, out of historic fetchmail behaviour.
              It controls both the SSL/TLS protocol version and, if  --ssl  is
              not specified, the STARTTLS behaviour (upgrading the protocol to
              an SSL or TLS connection in-band). Some other options  may  how-
              ever make TLS mandatory.
       Only  if  this option and --ssl are both missing for a poll, there will
       be opportunistic TLS for POP3 and IMAP, where fetchmail will attempt to
       upgrade to TLSv1 or newer.
       Recognized  values  for --sslproto are given below. You should normally
       chose one of the auto-negotiating options, i. e. 'auto' or one  of  the
       options  ending in a plus (+) character. Note that depending on OpenSSL
       library version and configuration, some options cause  run-time  errors
       because the requested SSL or TLS versions are not supported by the par-
       ticular installed OpenSSL library.
              '', the empty string
                     Disable STARTTLS. If --ssl is given for the same  server,
                     log  an  error  and  pretend  that  'auto'  had been used
                     instead.
              'auto' (default). Require TLS. Auto-negotiate  TLSv1  or  newer,
                     disable SSLv3 downgrade.  (previous releases of fetchmail
                     have auto-negotiated all  protocols  that  their  OpenSSL
                     library supported, including the broken SSLv3).
              'SSL23'
                     see 'auto'.
              'SSL2' Require  SSLv2 exactly. SSLv2 is broken, not supported on
                     all systems, avoid it if possible. This will make  fetch-
                     mail  negotiate  SSLv2  only, and is the only way to have
                     fetchmail permit SSLv2.
              'SSL3' Require SSLv3 exactly. SSLv3 is broken, not supported  on
                     all  systems, avoid it if possible. This will make fetch-
                     mail negotiate SSLv3 only, and is the  only  way  besides
                     'SSL3+' to have fetchmail permit SSLv3.
              'SSL3+'
                     same  as  'auto',  but  permit SSLv3 as well. This is the
                     only way besides 'SSL3' to have fetchmail permit SSLv3.
              'TLS1' Require TLSv1. This does not negotiate TLSv1.1 or  newer,
                     and  is  discouraged.  Replace by TLS1+ unless the latter
                     chokes your server.
              'TLS1+'
                     See 'auto'.
              'TLS1.1'
                     Require TLS v1.1 exactly.
              'TLS1.1+'
                     Require TLS. Auto-negotiate TLSv1.1 or newer.
              'TLS1.2'
                     Require TLS v1.2 exactly.
              'TLS1.2+'
                     Require TLS. Auto-negotiate TLSv1.2 or newer.
              Unrecognized parameters
                     are treated the same as 'auto'.
              NOTE: you should hardly ever need to use anything other than  ''
              (to force an unencrypted connection) or 'auto' (to enforce TLS).
       --sslcertck
              (Keyword: sslcertck)
              Causes  fetchmail to require that SSL/TLS be used and disconnect
              if it can not successfully negotiate SSL or TLS, or if it cannot
              successfully  verify  and validate the certificate and follow it
              to a trust anchor  (or  trusted  root  certificate).  The  trust
              anchors  are  given  as a set of local trusted certificates (see
              the sslcertfile and sslcertpath options). If the server certifi-
              cate  cannot  be obtained or is not signed by one of the trusted
              ones  (directly  or  indirectly),  fetchmail  will   disconnect,
              regardless of the sslfingerprint option.
              Note  that CRL (certificate revocation lists) are only supported
              in OpenSSL 0.9.7 and newer! Your system  clock  should  also  be
              reasonably accurate when using this option.
              Note  that this optional behavior may become default behavior in
              future fetchmail versions.
       --sslcertfile <file>
              (Keyword: sslcertfile, since v6.3.17)
              Sets the file fetchmail uses to look up local certificates.  The
              default  is  empty.  This can be given in addition to --sslcert-
              path below, and certificates specified in --sslcertfile will  be
              processed before those in --sslcertpath.  The option can be used
              in addition to --sslcertpath.
              The file is a  text  file.  It  contains  the  concatenation  of
              trusted CA certificates in PEM format.
              Note  that  using  this option will suppress loading the default
              SSL trusted CA certificates file unless you set the  environment
              variable  FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS to a non-empty
              value.
       --sslcertpath <directory>
              (Keyword: sslcertpath)
              Sets the directory fetchmail uses to look up local certificates.
              The  default  is  your  OpenSSL default directory. The directory
              must be hashed the way OpenSSL expects it - every time  you  add
              or  modify  a  certificate in the directory, you need to use the
              c_rehash tool (which comes with OpenSSL in the tools/  subdirec-
              tory).  Also,  after  OpenSSL  upgrades,  you  may  need  to run
              c_rehash; particularly when upgrading from 0.9.X to 1.0.0.
              This can be given in addition to --sslcertfile above, which  see
              for precedence rules.
              Note that using this option will suppress adding the default SSL
              trusted CA certificates directory unless you set the environment
              variable  FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS to a non-empty
              value.
       --sslcommonname <common name>
              (Keyword: sslcommonname; since v6.3.9)
              Use of this option is discouraged. Before using it, contact  the
              administrator  of  your upstream server and ask for a proper SSL
              certificate to be used. If that cannot be attained, this  option
              can  be  used  to  specify  the name (CommonName) that fetchmail
              expects on  the  server  certificate.   A  correctly  configured
              server  will  have  this  set  to  the  hostname  by which it is
              reached, and by default fetchmail will expect as much. Use  this
              option  when the CommonName is set to some other value, to avoid
              the "Server  CommonName  mismatch"  warning,  and  only  if  the
              upstream server can't be made to use proper certificates.
       --sslfingerprint <fingerprint>
              (Keyword: sslfingerprint)
              Specify  the  fingerprint  of the server key (an MD5 hash of the
              key) in hexadecimal notation with colons  separating  groups  of
              two digits. The letter hex digits must be in upper case. This is
              the default format OpenSSL uses, and the one fetchmail  uses  to
              report  the  fingerprint  when an SSL connection is established.
              When this is specified, fetchmail will compare  the  server  key
              fingerprint  with the given one, and the connection will fail if
              they do not match regardless of the sslcertck setting. The  con-
              nection  will  also  fail if fetchmail cannot obtain an SSL cer-
              tificate from the server.  This can be used to  prevent  man-in-
              the-middle  attacks,  but the finger print from the server needs
              to be obtained or verified over a secure channel, and  certainly
              not over the same Internet connection that fetchmail would use.
              Using this option will prevent printing certificate verification
              errors as long as --sslcertck is unset.
              To obtain the fingerprint of a certificate stored  in  the  file
              cert.pem, try:
                   openssl x509 -in cert.pem -noout -md5 -fingerprint
              For details, see x509(1ssl).
   Delivery Control Options
       -S <hosts> | --smtphost <hosts>
              (Keyword: smtp[host])
              Specify  a  hunt  list  of hosts to forward mail to (one or more
              hostnames, comma-separated). Hosts are tried in list order;  the
              first  one that is up becomes the forwarding target for the cur-
              rent run.  If this option is not specified, 'localhost' is  used
              as  the default.  Each hostname may have a port number following
              the host name.  The port number is separated from the host  name
              by a slash; the default port is "smtp".  If you specify an abso-
              lute path name (beginning with a /), it will be  interpreted  as
              the name of a UNIX socket accepting LMTP connections (such as is
              supported by the Cyrus IMAP daemon) Example:
                   --smtphost server1,server2/2525,server3,/var/imap/socket/lmtp
              This option can be used with ODMR, and  will  make  fetchmail  a
              relay between the ODMR server and SMTP or LMTP receiver.
       --fetchdomains <hosts>
              (Keyword: fetchdomains)
              In  ETRN or ODMR mode, this option specifies the list of domains
              the server should ship mail for once the  connection  is  turned
              around.   The  default is the FQDN of the machine running fetch-
              mail.
       -D <domain> | --smtpaddress <domain>
              (Keyword: smtpaddress)
              Specify the domain to be appended to addresses in RCPT TO  lines
              shipped  to  SMTP.  When  this is not specified, the name of the
              SMTP server (as specified by --smtphost) is used  for  SMTP/LMTP
              and 'localhost' is used for UNIX socket/BSMTP.
       --smtpname <user@domain>
              (Keyword: smtpname)
              Specify  the  domain and user to be put in RCPT TO lines shipped
              to SMTP.  The default user is the current local user.
       -Z <nnn> | --antispam <nnn[, nnn]...>
              (Keyword: antispam)
              Specifies the list of numeric SMTP errors that are to be  inter-
              preted  as  a spam-block response from the listener.  A value of
              -1 disables this option.  For the command-line option, the  list
              values should be comma-separated.
       -m <command> | --mda <command>
              (Keyword: mda)
              This option lets fetchmail use a Message or Local Delivery Agent
              (MDA or LDA) directly, rather than forward via SMTP or LMTP.
              To avoid losing mail, use this option only with MDAs like  mail-
              drop  or  MTAs  like sendmail that exit with a nonzero status on
              disk-full and other delivery errors; the  nonzero  status  tells
              fetchmail  that  delivery  failed  and prevents the message from
              being deleted on the server.
              If fetchmail is running as root,  it  sets  its  user  id  while
              delivering  mail  through  an MDA as follows:  First, the FETCH-
              MAILUSER, LOGNAME, and USER environment variables are checked in
              this  order.  The value of the first variable from his list that
              is defined (even if it is empty!) is looked  up  in  the  system
              user  database.  If  none of the variables is defined, fetchmail
              will use the real user id it was started with.  If  one  of  the
              variables  was  defined,  but the user stated there isn't found,
              fetchmail continues running as root, without checking  remaining
              variables  on the list.  Practically, this means that if you run
              fetchmail as root (not recommended), it is most useful to define
              the  FETCHMAILUSER environment variable to set the user that the
              MDA should run as. Some MDAs (such as maildrop) are designed  to
              be  setuid  root  and  setuid to the recipient's user id, so you
              don't lose functionality this way even when running fetchmail as
              unprivileged user.  Check the MDA's manual for details.
              Some  possible  MDAs  are  "/usr/sbin/sendmail  -i  -f %F -- %T"
              (Note: some several older or vendor sendmail versions mistake --
              for  an address, rather than an indicator to mark the end of the
              option arguments), "/usr/bin/deliver" and "/usr/bin/maildrop  -d
              %T".   Local  delivery  addresses  will be inserted into the MDA
              command wherever you place a %T; the mail message's From address
              will be inserted where you place an %F.
              Do  NOT  enclose the %F or %T string in single quotes!  For both
              %T and %F, fetchmail encloses the  addresses  in  single  quotes
              ('),  after  removing any single quotes they may contain, before
              the MDA command is passed to the shell.
              Do NOT use an MDA invocation that dispatches on the contents  of
              To/Cc/Bcc, like "sendmail -i -t" or "qmail-inject", it will cre-
              ate mail loops and bring the just wrath of many postmasters down
              upon  your head.  This is one of the most frequent configuration
              errors!
              Also, do not try to combine multidrop mode with an MDA  such  as
              maildrop  that can only accept one address, unless your upstream
              stores one copy of the message per recipient and transports  the
              envelope recipient in a header; you will lose mail.
              The  well-known  procmail(1)  package  is very hard to configure
              properly, it has a very nasty "fall through to  the  next  rule"
              behavior on delivery errors (even temporary ones, such as out of
              disk space if another user's  mail  daemon  copies  the  mailbox
              around  to  purge old messages), so your mail will end up in the
              wrong mailbox sooner or later. The proper procmail configuration
              is outside the scope of this document. Using maildrop(1) is usu-
              ally much easier, and many users find the filter syntax used  by
              maildrop easier to understand.
              Finally,  we  strongly  advise that you do not use qmail-inject.
              The command line interface  is  non-standard  without  providing
              benefits  for  typical  use,  and fetchmail makes no attempts to
              accommodate qmail-inject's deviations from the standard. Some of
              qmail-inject's command-line and environment options are actually
              dangerous and can cause broken threads,  non-detected  duplicate
              messages and forwarding loops.

       --lmtp (Keyword: lmtp)
              Cause  delivery via LMTP (Local Mail Transfer Protocol).  A ser-
              vice host and port must be explicitly specified on each host  in
              the  smtphost  hunt list (see above) if this option is selected;
              the default port 25 will (in accordance with RFC  2033)  not  be
              accepted.
       --bsmtp <filename>
              (Keyword: bsmtp)
              Append  fetched  mail to a BSMTP file.  This simply contains the
              SMTP commands that would normally be generated by fetchmail when
              passing mail to an SMTP listener daemon.
              An  argument of '-' causes the SMTP batch to be written to stan-
              dard output, which is of limited use: this only makes sense  for
              debugging, because fetchmail's regular output is interspersed on
              the same channel, so this isn't suitable for mail delivery. This
              special mode may be removed in a later release.
              Note  that  fetchmail's  reconstruction of MAIL FROM and RCPT TO
              lines is not guaranteed correct; the caveats discussed under THE
              USE AND ABUSE OF MULTIDROP MAILBOXES below apply.  This mode has
              precedence before --mda and SMTP/LMTP.
       --bad-header {reject|accept}
              (Keyword: bad-header; since v6.3.15)
              Specify how fetchmail is supposed to  treat  messages  with  bad
              headers, i. e. headers with bad syntax. Traditionally, fetchmail
              has rejected  such  messages,  but  some  distributors  modified
              fetchmail  to accept them. You can now configure fetchmail's be-
              haviour per server.

   Resource Limit Control Options
       -l <maxbytes> | --limit <maxbytes>
              (Keyword: limit)
              Takes a maximum octet size argument, where 0 is the default  and
              also the special value designating "no limit".  If nonzero, mes-
              sages larger than this size will not be fetched and will be left
              on  the  server  (in  foreground sessions, the progress messages
              will note that they are "oversized").   If  the  fetch  protocol
              permits  (in particular, under IMAP or POP3 without the fetchall
              option) the message will not be marked seen.
              An explicit --limit of 0 overrides any limits set  in  your  run
              control  file.  This  option  is  intended  for those needing to
              strictly control fetch time due to expensive and variable  phone
              rates.
              Combined  with  --limitflush, it can be used to delete oversized
              messages waiting on a server.  In daemon mode, oversize  notifi-
              cations  are  mailed  to  the  calling  user (see the --warnings
              option). This option does not work with ETRN or ODMR.
       -w <interval> | --warnings <interval>
              (Keyword: warnings)
              Takes an interval in seconds.  When you call  fetchmail  with  a
              'limit'  option  in  daemon  mode, this controls the interval at
              which warnings about oversized messages are mailed to the  call-
              ing  user  (or  the  user specified by the 'postmaster' option).
              One such notification is always mailed at the  end  of  the  the
              first  poll that the oversized message is detected.  Thereafter,
              re-notification is suppressed until after the  warning  interval
              elapses  (it  will  take place at the end of the first following
              poll).
       -b <count> | --batchlimit <count>
              (Keyword: batchlimit)
              Specify the maximum number of messages that will be  shipped  to
              an SMTP listener before the connection is deliberately torn down
              and rebuilt (defaults to 0,  meaning  no  limit).   An  explicit
              --batchlimit  of  0 overrides any limits set in your run control
              file.  While sendmail(8) normally initiates delivery of  a  mes-
              sage  immediately  after  receiving the message terminator, some
              SMTP listeners are not so prompt.  MTAs like smail(8)  may  wait
              till the delivery socket is shut down to deliver.  This may pro-
              duce annoying delays when fetchmail  is  processing  very  large
              batches.  Setting the batch limit to some nonzero size will pre-
              vent these delays.  This option does not work with ETRN or ODMR.
       -B <number> | --fetchlimit <number>
              (Keyword: fetchlimit)
              Limit the number of messages accepted from a given server  in  a
              single poll.  By default there is no limit. An explicit --fetch-
              limit of 0 overrides any limits set in your  run  control  file.
              This option does not work with ETRN or ODMR.
       --fetchsizelimit <number>
              (Keyword: fetchsizelimit)
              Limit  the  number  of  sizes  of messages accepted from a given
              server in a single transaction.  This option is useful in reduc-
              ing  the  delay in downloading the first mail when there are too
              many mails in the mailbox.  By default, the limit  is  100.   If
              set  to  0,  sizes  of all messages are downloaded at the start.
              This option does not work with ETRN or ODMR.  For POP3, the only
              valid non-zero value is 1.
       --fastuidl <number>
              (Keyword: fastuidl)
              Do  a  binary instead of linear search for the first unseen UID.
              Binary search avoids downloading the UIDs  of  all  mails.  This
              saves  time  (especially  in  daemon mode) where downloading the
              same set of UIDs in each poll is a waste of bandwidth. The  num-
              ber  'n' indicates how rarely a linear search should be done. In
              daemon mode, linear search  is  used  once  followed  by  binary
              searches  in 'n-1' polls if 'n' is greater than 1; binary search
              is always used if 'n' is 1; linear search is always used if  'n'
              is  0.  In  non-daemon  mode, binary search is used if 'n' is 1;
              otherwise linear search is used. The default value of 'n' is  4.
              This option works with POP3 only.
       -e <count> | --expunge <count>
              (Keyword: expunge)
              Arrange  for  deletions to be made final after a given number of
              messages.  Under POP2 or POP3, fetchmail cannot  make  deletions
              final  without  sending QUIT and ending the session -- with this
              option on, fetchmail will break a long  mail  retrieval  session
              into multiple sub-sessions, sending QUIT after each sub-session.
              This is a good defense  against  line  drops  on  POP3  servers.
              Under  IMAP,  fetchmail normally issues an EXPUNGE command after
              each deletion in order to force the deletion to be done  immedi-
              ately.   This  is  safest  when your connection to the server is
              flaky and expensive, as it avoids resending duplicate mail after
              a  line  hit.   However,  on large mailboxes the overhead of re-
              indexing after every message can slam the server pretty hard, so
              if  your  connection  is reliable it is good to do expunges less
              frequently.  Also note that some servers enforce a  delay  of  a
              few seconds after each quit, so fetchmail may not be able to get
              back in immediately after an expunge -- you may see "lock  busy"
              errors if this happens. If you specify this option to an integer
              N, it tells fetchmail  to  only  issue  expunges  on  every  Nth
              delete.  An argument of zero suppresses expunges entirely (so no
              expunges at all will be done until the end of run).  This option
              does not work with ETRN or ODMR.

   Authentication Options
       -u <name> | --user <name> | --username <name>
              (Keyword: user[name])
              Specifies  the user identification to be used when logging in to
              the mailserver.  The appropriate  user  identification  is  both
              server  and  user-dependent.   The default is your login name on
              the client machine that is running fetchmail.  See USER  AUTHEN-
              TICATION below for a complete description.
       -I <specification> | --interface <specification>
              (Keyword: interface)
              Require  that  a specific interface device be up and have a spe-
              cific local or remote IPv4 (IPv6 is not supported by this option
              yet) address (or range) before polling.  Frequently fetchmail is
              used over a transient  point-to-point  TCP/IP  link  established
              directly  to a mailserver via SLIP or PPP.  That is a relatively
              secure channel.  But when other TCP/IP routes to the  mailserver
              exist  (e.g.  when  the  link is connected to an alternate ISP),
              your username and password may be vulnerable to snooping  (espe-
              cially when daemon mode automatically polls for mail, shipping a
              clear password over the  net  at  predictable  intervals).   The
              --interface option may be used to prevent this.  When the speci-
              fied link is not up  or  is  not  connected  to  a  matching  IP
              address, polling will be skipped.  The format is:
                   interface/iii.iii.iii.iii[/mmm.mmm.mmm.mmm]
              The  field  before  the  first slash is the interface name (i.e.
              sl0, ppp0 etc.).  The field  before  the  second  slash  is  the
              acceptable  IP  address.   The field after the second slash is a
              mask which specifies a range of IP addresses to accept.   If  no
              mask  is  present  255.255.255.255  is  assumed  (i.e.  an exact
              match).  This option is currently only supported under Linux and
              FreeBSD.  Please  see  the monitor section for below for FreeBSD
              specific information.
              Note that this option may be removed  from  a  future  fetchmail
              version.
       -M <interface> | --monitor <interface>
              (Keyword: monitor)
              Daemon  mode  can  cause transient links which are automatically
              taken down after a period of  inactivity  (e.g.  PPP  links)  to
              remain  up indefinitely.  This option identifies a system TCP/IP
              interface to be monitored for activity.  After each poll  inter-
              val, if the link is up but no other activity has occurred on the
              link, then the poll will be skipped.  However, when fetchmail is
              woken  up by a signal, the monitor check is skipped and the poll
              goes through unconditionally.  This  option  is  currently  only
              supported  under  Linux and FreeBSD.  For the monitor and inter-
              face options to work for  non  root  users  under  FreeBSD,  the
              fetchmail  binary  must be installed SGID kmem.  This would be a
              security hole, but fetchmail runs with the effective GID set  to
              that  of  the  kmem group only when interface data is being col-
              lected.
              Note that this option may be removed  from  a  future  fetchmail
              version.
       --auth <type>
              (Keyword: auth[enticate])
              This  option  permits you to specify an authentication type (see
              USER AUTHENTICATION below for details).  The possible values are
              any,  password,  kerberos_v5,  kerberos  (or,  for  excruciating
              exactness, kerberos_v4), gssapi, cram-md5, otp, ntlm, msn  (only
              for POP3), external (only IMAP) and ssh.  When any (the default)
              is specified, fetchmail tries first methods that don't require a
              password  (EXTERNAL,  GSSAPI,  KERBEROS IV, KERBEROS 5); then it
              looks for methods that mask your password (CRAM-MD5, NTLM, X-OTP
              - note that MSN is only supported for POP3, but not autoprobed);
              and only if the server doesn't support any of those will it ship
              your password en clair.  Other values may be used to force vari-
              ous authentication methods (ssh suppresses authentication and is
              thus useful for IMAP PREAUTH).  (external suppresses authentica-
              tion and is thus useful for IMAP  EXTERNAL).   Any  value  other
              than password, cram-md5, ntlm, msn or otp suppresses fetchmail's
              normal inquiry for a password.  Specify ssh when you  are  using
              an  end-to-end  secure connection such as an ssh tunnel; specify
              external when you use TLS with client authentication and specify
              gssapi  or  kerberos_v4 if you are using a protocol variant that
              employs GSSAPI or  K4.   Choosing  KPOP  protocol  automatically
              selects Kerberos authentication.  This option does not work with
              ETRN.  GSSAPI service names are in line with RFC-2743  and  IANA
              registrations, see Generic Security Service Application Program
              Interface (GSSAPI)/Kerberos/Simple Authentication and Security
              Layer (SASL) Service Names <http://www.iana.org/assignments/
              gssapi-service-names/>.
   Miscellaneous Options
       -f <pathname> | --fetchmailrc <pathname>
              Specify a non-default name for the  ~/.fetchmailrc  run  control
              file.   The pathname argument must be either "-" (a single dash,
              meaning to read the configuration  from  standard  input)  or  a
              filename.   Unless the --version option is also on, a named file
              argument  must  have  permissions  no  more   open   than   0700
              (u=rwx,g=,o=) or else be /dev/null.
       -i <pathname> | --idfile <pathname>
              (Keyword: idfile)
              Specify  an  alternate  name for the .fetchids file used to save
              message UIDs. NOTE: since fetchmail 6.3.0, write access  to  the
              directory containing the idfile is required, as fetchmail writes
              a temporary file and renames it  into  the  place  of  the  real
              idfile only if the temporary file has been written successfully.
              This avoids the truncation of idfiles when running out  of  disk
              space.
       --pidfile <pathname>
              (Keyword: pidfile; since fetchmail v6.3.4)
              Override  the  default  location  of  the PID file. Default: see
              "ENVIRONMENT" below.
       -n | --norewrite
              (Keyword: no rewrite)
              Normally, fetchmail edits RFC-822 address headers (To, From, Cc,
              Bcc, and Reply-To) in fetched mail so that any mail IDs local to
              the server are expanded to full addresses (@ and the  mailserver
              hostname  are  appended).  This enables replies on the client to
              get addressed correctly (otherwise your mailer might think  they
              should  be  addressed  to  local  users on the client machine!).
              This option disables the rewrite.  (This option is  provided  to
              pacify  people  who  are  paranoid about having an MTA edit mail
              headers and want to know they can prevent it, but it  is  gener-
              ally  not a good idea to actually turn off rewrite.)  When using
              ETRN or ODMR, the rewrite option is ineffective.
       -E <line> | --envelope <line>
              (Keyword: envelope; Multidrop only)
              In the configuration file, an enhanced syntax is used:
              envelope [<count>] <line>
              This option changes the header fetchmail assumes  will  carry  a
              copy  of the mail's envelope address.  Normally this is 'X-Enve-
              lope-To'.  Other  typically  found  headers  to  carry  envelope
              information  are 'X-Original-To' and 'Delivered-To'.  Now, since
              these headers are not standardized,  practice  varies.  See  the
              discussion  of  multidrop  address handling below.  As a special
              case, 'envelope "Received"' enables  parsing  of  sendmail-style
              Received lines.  This is the default, but discouraged because it
              is not fully reliable.
              Note that fetchmail expects the Received-line to be  in  a  spe-
              cific  format: It must contain "by host for address", where host
              must match one of the mailserver names that fetchmail recognizes
              for the account in question.
              The optional count argument (only available in the configuration
              file) determines how many header lines of this kind are skipped.
              A  count of 1 means: skip the first, take the second. A count of
              2 means: skip the first and second, take the third, and so on.
       -Q <prefix> | --qvirtual <prefix>
              (Keyword: qvirtual; Multidrop only)
              The string prefix assigned to this option will be  removed  from
              the  user  name  found in the header specified with the envelope
              option (before  doing  multidrop  name  mapping  or  localdomain
              checking, if either is applicable). This option is useful if you
              are using fetchmail to collect the mail for an entire domain and
              your  ISP  (or  your  mail redirection provider) is using qmail.
              One of the basic features of qmail is the Delivered-To:  message
              header.  Whenever qmail delivers a message to a local mailbox it
              puts the username and hostname of the envelope recipient on this
              line.   The  major reason for this is to prevent mail loops.  To
              set up qmail to batch mail for a disconnected site the ISP-mail-
              host will have normally put that site in its 'Virtualhosts' con-
              trol file so it will add a prefix to all mail addresses for this
              site.  This  results  in  mail  sent to 'username AT userhost.user-
              dom.dom.com' having a Delivered-To: line of the form:
              Delivered-To: mbox-userstr-username AT userhost.com
              The ISP can make the 'mbox-userstr-' prefix anything they choose
              but  a  string  matching the user host name is likely.  By using
              the option 'envelope Delivered-To:' you can make fetchmail reli-
              ably  identify  the original envelope recipient, but you have to
              strip the 'mbox-userstr-' prefix to deliver to the correct user.
              This is what this option is for.
       --configdump
              Parse   the  ~/.fetchmailrc  file,  interpret  any  command-line
              options specified, and dump a configuration report  to  standard
              output.  The configuration report is a data structure assignment
              in the language Python.  This option is meant to be used with an
              interactive ~/.fetchmailrc editor like fetchmailconf, written in
              Python.
       -y | --yydebug
              Enables parser debugging, this option is meant  to  be  used  by
              developers only.

   Removed Options
       -T | --netsec
              Removed before version 6.3.0, the required underlying inet6_apps
              library had been discontinued and is no longer available.

USER AUTHENTICATION AND ENCRYPTION
       All modes except ETRN require  authentication  of  the  client  to  the
       server.   Normal user authentication in fetchmail is very much like the
       authentication mechanism of ftp(1).  The correct user-id  and  password
       depend upon the underlying security system at the mailserver.
       If  the mailserver is a Unix machine on which you have an ordinary user
       account, your regular login name and password are used with  fetchmail.
       If  you  use  the  same  login  name  on both the server and the client
       machines, you needn't worry about specifying  a  user-id  with  the  -u
       option  -- the default behavior is to use your login name on the client
       machine as the user-id on the server machine.  If you use  a  different
       login  name  on the server machine, specify that login name with the -u
       option.  e.g. if your login name is 'jsmith' on a machine named  'mail-
       grunt', you would start fetchmail as follows:
              fetchmail -u jsmith mailgrunt
       The  default behavior of fetchmail is to prompt you for your mailserver
       password before the connection is established.  This is the safest  way
       to  use  fetchmail  and  ensures that your password will not be compro-
       mised.  You may also specify your password in your ~/.fetchmailrc file.
       This is convenient when using fetchmail in daemon mode or with scripts.

   Using netrc files
       If you do not specify a password, and fetchmail cannot extract one from
       your ~/.fetchmailrc file, it will look for a ~/.netrc file in your home
       directory before requesting one interactively; if an entry matching the
       mailserver is found in that file, the password will be used.  Fetchmail
       first looks for a match on poll name; if it finds none, it checks for a
       match on via name.  See the ftp(1) man page for details of  the  syntax
       of the ~/.netrc file.  To show a practical example, a .netrc might look
       like this:
              machine hermes.example.org
              login joe
              password topsecret
       You can repeat this block with different user information if  you  need
       to provide more than one password.
       This feature may allow you to avoid duplicating password information in
       more than one file.
       On mailservers that do not provide ordinary user accounts, your user-id
       and  password are usually assigned by the server administrator when you
       apply for a mailbox on the server.  Contact your  server  administrator
       if  you  don't  know  the correct user-id and password for your mailbox
       account.
POP3 VARIANTS
       Early versions of POP3 (RFC1081, RFC1225) supported  a  crude  form  of
       independent  authentication  using  the  .rhosts file on the mailserver
       side.  Under this RPOP variant, a fixed per-user  ID  equivalent  to  a
       password  was  sent  in  clear over a link to a reserved port, with the
       command RPOP rather than PASS to alert the server  that  it  should  do
       special  checking.   RPOP  is  supported  by fetchmail (you can specify
       'protocol RPOP' to have the program send 'RPOP' rather than 'PASS') but
       its  use  is  strongly  discouraged, and support will be removed from a
       future fetchmail version.  This facility was vulnerable to spoofing and
       was withdrawn in RFC1460.
       RFC1460  introduced  APOP authentication.  In this variant of POP3, you
       register an APOP password on your server host  (on  some  servers,  the
       program to do this is called popauth(8)).  You put the same password in
       your ~/.fetchmailrc file.  Each time fetchmail logs in, it sends an MD5
       hash of your password and the server greeting time to the server, which
       can verify it by checking its authorization database.
       Note that APOP is no longer considered  resistant  against  man-in-the-
       middle attacks.
   RETR or TOP
       fetchmail  makes  some  efforts to make the server believe messages had
       not been retrieved, by using the TOP command with  a  large  number  of
       lines  when  possible.  TOP is a command that retrieves the full header
       and a fetchmail-specified amount of body  lines.  It  is  optional  and
       therefore  not implemented by all servers, and some are known to imple-
       ment it improperly. On many servers however,  the  RETR  command  which
       retrieves  the  full message with header and body, sets the "seen" flag
       (for instance, in a web interface), whereas the TOP command does not do
       that.
       fetchmail  will  always  use  the  RETR  command  if "fetchall" is set.
       fetchmail will also use the RETR command if "keep" is set and "uidl" is
       unset.   Finally,  fetchmail  will  use the RETR command on Maillennium
       POP3/PROXY servers (used by Comcast) to avoid a deliberate  TOP  misin-
       terpretation in this server that causes message corruption.
       In  all  other  cases, fetchmail will use the TOP command. This implies
       that in "keep" setups, "uidl" must be set if "TOP" is desired.
       Note that this description is true for the current  version  of  fetch-
       mail,  but  the  behavior may change in future versions. In particular,
       fetchmail may prefer the RETR command because the  TOP  command  causes
       much grief on some servers and is only optional.
ALTERNATE AUTHENTICATION FORMS
       If  your fetchmail was built with Kerberos support and you specify Ker-
       beros authentication (either with --auth  or  the  .fetchmailrc  option
       authenticate kerberos_v4) it will try to get a Kerberos ticket from the
       mailserver at the start of each query.  Note: if either the pollname or
       via  name  is 'hesiod', fetchmail will try to use Hesiod to look up the
       mailserver.
       If you use POP3 or IMAP  with  GSSAPI  authentication,  fetchmail  will
       expect  the  server to have RFC1731- or RFC1734-conforming GSSAPI capa-
       bility, and will use it.  Currently this has only been tested over Ker-
       beros  V,  so you're expected to already have a ticket-granting ticket.
       You may pass a username different from your principal  name  using  the
       standard --user command or by the .fetchmailrc option user.
       If  your IMAP daemon returns the PREAUTH response in its greeting line,
       fetchmail will notice this and skip  the  normal  authentication  step.
       This  can  be useful, e.g. if you start imapd explicitly using ssh.  In
       this case you can declare the authentication value 'ssh' on  that  site
       entry  to stop .fetchmail from asking you for a password when it starts
       up.
       If you use client authentication with TLS1 and your IMAP daemon returns
       the AUTH=EXTERNAL response, fetchmail will notice this and will use the
       authentication shortcut and will not send the passphrase. In this  case
       you can declare the authentication value 'external'
        on  that site to stop fetchmail from asking you for a password when it
       starts up.
       If you are using POP3, and the server issues a one-time-password  chal-
       lenge conforming to RFC1938, fetchmail will use your password as a pass
       phrase to generate the required response. This avoids  sending  secrets
       over the net unencrypted.
       Compuserve's  RPA  authentication  is  supported. If you compile in the
       support, fetchmail will try to perform an RPA  pass-phrase  authentica-
       tion instead of sending over the password en clair if it detects "@com-
       puserve.com" in the hostname.
       If you are using IMAP, Microsoft's NTLM authentication (used by  Micro-
       soft  Exchange)  is supported. If you compile in the support, fetchmail
       will try to perform an NTLM authentication (instead of sending over the
       password  en  clair) whenever the server returns AUTH=NTLM in its capa-
       bility  response.  Specify  a  user  option  value  that   looks   like
       'user@domain':  the  part  to  the  left of the @ will be passed as the
       username and the part to the right as the NTLM domain.

   Secure Socket Layers (SSL) and Transport Layer Security (TLS)
       transport. Additionally, POP3 and  IMAP  retrival  can  also  negotiate
       SSL/TLS by means of STARTTLS (or STLS).
       Note  that  fetchmail  currently uses the OpenSSL library, which is se-
       verely underdocumented, so failures may occur just because the program-
       mers  are not aware of OpenSSL's requirement of the day.  For instance,
       since v6.3.16, fetchmail calls OpenSSL_add_all_algorithms(),  which  is
       necessary to support certificates using SHA256 on OpenSSL 0.9.8 -- this
       information is deeply hidden in the documentation and not at all  obvi-
       ous.  Please do not hesitate to report subtle SSL failures.
       You  can access SSL encrypted services by specifying the options start-
       ing with --ssl, such as --ssl,  --sslproto,  --sslcertck,  and  others.
       You  can  also  do  this  using  the  corresponding user options in the
       .fetchmailrc file.  Some services, such as POP3 and IMAP, have  differ-
       ent  well  known  ports  defined  for  the SSL encrypted services.  The
       encrypted ports will be selected automatically when SSL is enabled  and
       no  explicit port is specified.   Also, the --sslcertck command line or
       sslcertck run control file option should be used to force  strict  cer-
       tificate checking - see below.
       If  SSL is not configured, fetchmail will usually opportunistically try
       to use STARTTLS. STARTTLS can be enforced by using --sslproto auto  and
       defeated  by using --sslproto ''.  TLS connections use the same port as
       the unencrypted version of the protocol and negotiate TLS  via  special
       command.  The  --sslcertck  command  line or sslcertck run control file
       option should be used to force strict certificate checking - see below.
       --sslcertck is recommended: When connecting to an SSL or TLS  encrypted
       server, the server presents a certificate to the client for validation.
       The certificate is checked to verify that the common name in  the  cer-
       tificate  matches  the  name of the server being contacted and that the
       effective and expiration dates in the certificate indicate that  it  is
       currently  valid.   If  any  of these checks fail, a warning message is
       printed, but the connection continues.  The server certificate does not
       need  to  be  signed  by any specific Certifying Authority and may be a
       "self-signed" certificate. If the --sslcertck command  line  option  or
       sslcertck run control file option is used, fetchmail will instead abort
       if any of these checks fail, because it must assume  that  there  is  a
       man-in-the-middle  attack  in  this  scenario, hence fetchmail must not
       expose cleartext passwords. Use of the sslcertck or --sslcertck  option
       is therefore advised.
       Some  SSL  encrypted  servers may request a client side certificate.  A
       client side public SSL certificate and private SSL key  may  be  speci-
       fied.   If  requested  by the server, the client certificate is sent to
       the server for validation.  Some servers may  require  a  valid  client
       certificate and may refuse connections if a certificate is not provided
       or if the certificate is not valid.  Some servers  may  require  client
       side  certificates be signed by a recognized Certifying Authority.  The
       format for the key files and the certificate files is that required  by
       the underlying SSL libraries (OpenSSL in the general case).
       A  word  of care about the use of SSL: While above mentioned setup with
       self-signed server certificates retrieved over the  wires  can  protect
       you  from  a  passive  eavesdropper,  it doesn't help against an active
       attacker. It's clearly an improvement over  sending  the  passwords  in
       clear, but you should be aware that a man-in-the-middle attack is triv-
       ially possible (in particular with tools such as dsniff <http://
       monkey.org/~dugsong/dsniff/>,  ).   Use  of strict certificate checking
       with a certification authority recognized by server and client, or per-
       haps  of  an  SSH tunnel (see below for some examples) is preferable if
       you care seriously about the security of your mailbox and passwords.

   ESMTP AUTH
       fetchmail also supports authentication  to  the  ESMTP  server  on  the
       client  side  according  to  RFC 2554.  You can specify a name/password
       pair to be used with the keywords 'esmtpname' and 'esmtppassword';  the
       former defaults to the username of the calling user.

DAEMON MODE
   Introducing the daemon mode
       In daemon mode, fetchmail puts itself into the background and runs for-
       ever, querying each specified  host  and  then  sleeping  for  a  given
       polling interval.
   Starting the daemon mode
       There  are  several  ways to make fetchmail work in daemon mode. On the
       command line, --daemon <interval> or -d <interval> option  runs  fetch-
       mail  in  daemon  mode.  You must specify a numeric argument which is a
       polling interval (time to wait after completing a whole poll cycle with
       the  last server and before starting the next poll cycle with the first
       server) in seconds.
       Example: simply invoking
              fetchmail -d 900
       will, therefore, poll all the hosts described  in  your  ~/.fetchmailrc
       file (except those explicitly excluded with the 'skip' verb) a bit less
       often than once every 15 minutes (exactly: 15 minutes + time  that  the
       poll takes).
       It  is  also  possible to set a polling interval in your ~/.fetchmailrc
       file by saying 'set daemon <interval>', where <interval> is an  integer
       number of seconds.  If you do this, fetchmail will always start in dae-
       mon mode unless you override it with the command-line option --daemon 0
       or -d0.
       Only  one  daemon process is permitted per user; in daemon mode, fetch-
       mail sets up a per-user lockfile to guarantee this.  (You  can  however
       cheat  and  set the FETCHMAILHOME environment variable to overcome this
       setting, but in that case, it is your responsibility to make  sure  you
       aren't polling the same server with two processes at the same time.)
   Awakening the background daemon
       Normally,  calling  fetchmail  with  a daemon in the background sends a
       wake-up signal to the daemon and quits without output.  The  background
       daemon  then  starts its next poll cycle immediately.  The wake-up sig-
       nal, SIGUSR1, can also be sent manually. The wake-up action also clears
       any  'wedged'  flags  indicating  that  connections  have wedged due to
       failed authentication or multiple timeouts.
   Terminating the background daemon
       The option -q or --quit will kill a running daemon process  instead  of
       waking  it up (if there is no such process, fetchmail will notify you).
       If the --quit option appears last on the command line,  fetchmail  will
       kill  the  running  daemon  process and then quit. Otherwise, fetchmail
       will first kill a running daemon process and then continue running with
       the other options.
   Useful options for daemon mode
       The -L <filename> or --logfile <filename> option (keyword: set logfile)
       is only effective when fetchmail is detached and in daemon  mode.  Note
       that  the  logfile  must exist before fetchmail is run, you can use the
       touch(1) command with the filename as its sole argument to create it.
       This option allows you to redirect status  messages  into  a  specified
       logfile  (follow  the  option  with  the logfile name).  The logfile is
       opened for append, so previous messages aren't deleted.  This  is  pri-
       marily  useful  for  debugging configurations. Note that fetchmail does
       not detect if the logfile is rotated, the logfile is only  opened  once
       when fetchmail starts. You need to restart fetchmail after rotating the
       logfile and before compressing it (if applicable).
       The --syslog option (keyword: set syslog) allows you to redirect status
       and error messages emitted to the syslog(3) system daemon if available.
       Messages are logged with an id of fetchmail, the facility LOG_MAIL, and
       priorities LOG_ERR, LOG_ALERT or LOG_INFO.  This option is intended for
       logging status and error messages which indicate the status of the dae-
       mon and the results while fetching mail from the server(s).  Error mes-
       sages for command line options and parsing the  .fetchmailrc  file  are
       still  written to stderr, or to the specified log file.  The --nosyslog
       option turns off use of syslog(3),  assuming  it's  turned  on  in  the
       ~/.fetchmailrc file.  This option is overridden, in certain situations,
       by --logfile (which see).
       The -N or --nodetach option suppresses backgrounding and detachment  of
       the  daemon  process  from  its  control  terminal.  This is useful for
       debugging or when fetchmail runs as the child of a  supervisor  process
       such  as init(8) or Gerrit Pape's runit(8).  Note that this also causes
       the logfile option to be ignored.
       Note that while running in daemon  mode  polling  a  POP2  or  IMAP2bis
       server,  transient  errors  (such  as DNS failures or sendmail delivery
       refusals) may force the fetchall option on for the duration of the next
       polling  cycle.  This is a robustness feature.  It means that if a mes-
       sage is fetched (and thus marked seen by the mailserver) but not deliv-
       ered  locally due to some transient error, it will be re-fetched during
       the next poll cycle.  (The IMAP logic  doesn't  delete  messages  until
       they're delivered, so this problem does not arise.)
       If  you touch or change the ~/.fetchmailrc file while fetchmail is run-
       ning in daemon mode, this will be detected at the beginning of the next
       poll  cycle.   When  a  changed  ~/.fetchmailrc  is detected, fetchmail
       rereads it and restarts from scratch (using exec(2); no state  informa-
       tion is retained in the new instance).  Note that if fetchmail needs to
       query for passwords, of that if you  break  the  ~/.fetchmailrc  file's
       syntax,  the  new  instance  will  softly  and  silently vanish away on
       startup.

ADMINISTRATIVE OPTIONS
       The --postmaster <name> option (keyword: set postmaster) specifies  the
       last-resort  username  to which multidrop mail is to be forwarded if no
       matching local recipient can be found. It is also used  as  destination
       of  undeliverable  mail  if  the  'bouncemail' global option is off and
       additionally for spam-blocked mail if the 'bouncemail' global option is
       off  and  the 'spambounce' global option is on. This option defaults to
       the user who invoked fetchmail.  If the invoking user is root, then the
       default of this option is the user 'postmaster'.  Setting postmaster to
       the empty string causes such mail as described above to be discarded  -
       this  however  is  usually a bad idea.  See also the description of the
       'FETCHMAILUSER' environment variable in the ENVIRONMENT section below.
       The --nobounce behaves like the  "set  no  bouncemail"  global  option,
       which see.
       The --invisible option (keyword: set invisible) tries to make fetchmail
       invisible.  Normally, fetchmail behaves like any other MTA would --  it
       generates  a  Received header into each message describing its place in
       the chain of transmission, and tells the MTA it forwards  to  that  the
       mail  came  from  the  machine  fetchmail itself is running on.  If the
       invisible option is on, the Received header is suppressed and fetchmail
       tries  to  spoof  the MTA it forwards to into thinking it came directly
       from the mailserver host.
       The --showdots option (keyword: set showdots) forces fetchmail to  show
       progress  dots even if the output goes to a file or fetchmail is not in
       verbose mode.  Fetchmail shows the dots by default when run  in  --ver-
       bose  mode  and  output  goes  to  console.  This  option is ignored in
       --silent mode.
       By specifying the --tracepolls option, you can  ask  fetchmail  to  add
       information to the Received header on the form "polling {label} account
       {user}", where {label} is the account label (from the specified rcfile,
       normally  ~/.fetchmailrc)  and  {user} is the username which is used to
       log on to the mail server. This header can be used  to  make  filtering
       email where no useful header information is available and you want mail
       from different accounts sorted into different  mailboxes  (this  could,
       for  example, occur if you have an account on the same server running a
       mailing list, and are subscribed to the list using that  account).  The
       default is not adding any such header.  In .fetchmailrc, this is called
       'tracepolls'.

RETRIEVAL FAILURE MODES
       The protocols fetchmail uses to talk to mailservers are next to bullet-
       proof.   In  normal operation forwarding to port 25, no message is ever
       deleted (or even marked for deletion) on the host until the  SMTP  lis-
       tener on the client side has acknowledged to fetchmail that the message
       has been either accepted for delivery or rejected due to a spam block.
       When forwarding to an MDA, however, there is more possibility of error.
       Some MDAs are 'safe' and reliably return a nonzero status on any deliv-
       ery error, even one due to temporary resource limits.  The  maildrop(1)
       program  is  like this; so are most programs designed as mail transport
       agents, such as sendmail(1), including the sendmail wrapper of  Postfix
       and exim(1).  These programs give back a reliable positive acknowledge-
       ment and can be used with the mda option with no  risk  of  mail  loss.
       Unsafe  MDAs,  though,  may return 0 even on delivery failure.  If this
       happens, you will lose mail.
       The normal mode of fetchmail is to try to download only 'new' messages,
       leaving  untouched  (and  undeleted)  messages  you  have  already read
       directly on the server (or fetched with a previous  fetchmail  --keep).
       But  you  may  find that messages you've already read on the server are
       being fetched (and deleted) even when you don't specify  --all.   There
       are several reasons this can happen.
       One  could  be  that  you're using POP2.  The POP2 protocol includes no
       representation of 'new' or 'old' state in messages, so  fetchmail  must
       treat  all messages as new all the time.  But POP2 is obsolete, so this
       is unlikely.
       A potential POP3 problem might be servers that insert messages  in  the
       middle of mailboxes (some VMS implementations of mail are rumored to do
       this).  The fetchmail code assumes that new messages  are  appended  to
       the  end  of  the  mailbox; when this is not true it may treat some old
       messages as new and vice versa.  Using UIDL whilst setting  fastuidl  0
       might fix this, otherwise, consider switching to IMAP.
       Yet  another  POP3  problem is that if they can't make tempfiles in the
       user's home directory, some POP3 servers will hand back an undocumented
       response that causes fetchmail to spuriously report "No mail".
       The  IMAP code uses the presence or absence of the server flag \Seen to
       decide whether or not a message is new.  This isn't the right thing  to
       do,  fetchmail should check the UIDVALIDITY and use UID, but it doesn't
       do that yet. Under Unix, it counts on your IMAP server  to  notice  the
       BSD-style  Status  flags set by mail user agents and set the \Seen flag
       from them when appropriate.  All Unix IMAP servers we know of do  this,
       though  it's  not  specified by the IMAP RFCs.  If you ever trip over a
       server that doesn't, the symptom will be that messages you have already
       read  on  your  host  will  look new to the server.  In this (unlikely)
       case, only messages you fetched with  fetchmail  --keep  will  be  both
       undeleted and marked old.
       In  ETRN and ODMR modes, fetchmail does not actually retrieve messages;
       instead, it asks the server's SMTP listener to start a queue  flush  to
       the client via SMTP.  Therefore it sends only undelivered messages.

SPAM FILTERING
       Many  SMTP listeners allow administrators to set up 'spam filters' that
       block unsolicited email from specified domains.  A MAIL  FROM  or  DATA
       line  that  triggers  this  feature  will elicit an SMTP response which
       (unfortunately) varies according to the listener.
       Newer versions of sendmail return an error code of 571.
       According to RFC2821, the correct thing to return in this situation  is
       550  "Requested  action not taken: mailbox unavailable" (the draft adds
       "[E.g., mailbox not found, no access, or command  rejected  for  policy
       reasons].").
       Older  versions  of the exim MTA return 501 "Syntax error in parameters
       or arguments".
       The postfix MTA runs 554 as an antispam response.
       Zmailer may reject code with a 500 response (followed  by  an  enhanced
       status code that contains more information).
       Return  codes which fetchmail treats as antispam responses and discards
       the message can be set with the 'antispam' option.  This is one of  the
       only  three  circumstance under which fetchmail ever discards mail (the
       others are the 552 and 553 errors described below, and the  suppression
       of multidropped messages with a message-ID already seen).
       If  fetchmail  is  fetching  from an IMAP server, the antispam response
       will be detected and the message rejected immediately after the headers
       have  been  fetched, without reading the message body.  Thus, you won't
       pay for downloading spam message bodies.
       By default, the list of antispam responses is empty.
       If the spambounce global option is on, mail that is spam-blocked  trig-
       gers an RFC1892/RFC1894 bounce message informing the originator that we
       do not accept mail from it. See also BUGS.

SMTP/ESMTP ERROR HANDLING
       Besides the spam-blocking  described  above,  fetchmail  takes  special
       actions on the following SMTP/ESMTP error responses
       452 (insufficient system storage)
            Leave the message in the server mailbox for later retrieval.
       552 (message exceeds fixed maximum message size)
            Delete the message from the server.  Send bounce-mail to the orig-
            inator.
       553 (invalid sending domain)
            Delete the message from  the  server.   Don't  even  try  to  send
            bounce-mail to the originator.
       Other errors trigger bounce mail back to the originator. See also BUGS.

THE RUN CONTROL FILE
       The  preferred  way to set up fetchmail is to write a .fetchmailrc file
       in your home directory (you may do this directly, with a  text  editor,
       or indirectly via fetchmailconf).  When there is a conflict between the
       command-line arguments and the arguments in this file, the command-line
       arguments take precedence.
       To  protect the security of your passwords, your ~/.fetchmailrc may not
       normally have more than 0700 (u=rwx,g=,o=) permissions; fetchmail  will
       complain and exit otherwise (this check is suppressed when --version is
       on).
       You may read the .fetchmailrc file as a list of commands to be executed
       when fetchmail is called with no arguments.
   Run Control Syntax
       Comments begin with a '#' and extend through the end of the line.  Oth-
       erwise the file consists of a series of server entries or global option
       statements in a free-format, token-oriented syntax.
       There are four kinds of tokens: grammar keywords, numbers (i.e. decimal
       digit sequences), unquoted  strings,  and  quoted  strings.   A  quoted
       string  is  bounded  by  double  quotes and may contain whitespace (and
       quoted digits are treated as a string).  Note that quoted strings  will
       also contain line feed characters if they run across two or more lines,
       unless you use a backslash to join  lines  (see  below).   An  unquoted
       string  is  any  whitespace-delimited  token  that  is neither numeric,
       string quoted nor contains the special characters  ',',  ';',  ':',  or
       '='.
       Any  amount  of  whitespace  separates tokens in server entries, but is
       otherwise ignored. You may use backslash escape sequences (\n  for  LF,
       \t  for  HT,  \b  for BS, \r for CR, \nnn for decimal (where nnn cannot
       start with a 0), \0ooo for octal, and \xhh for hex) to embed non-print-
       able  characters or string delimiters in strings.  In quoted strings, a
       backslash at the very end of a line will cause the backslash itself and
       the line feed (LF or NL, new line) character to be ignored, so that you
       can wrap long strings. Without the backslash at the line end, the  line
       feed character would become part of the string.
       Warning:  while  these  resemble C-style escape sequences, they are not
       the same.  fetchmail only supports these eight styles. C supports  more
       escape  sequences that consist of backslash (\) and a single character,
       but does not support decimal codes and does not require the  leading  0
       in octal notation.  Example: fetchmail interprets \233 the same as \xE9
       (Latin small letter e with acute), where  C  would  interpret  \233  as
       octal 0233 = \x9B (CSI, control sequence introducer).
       Each  server  entry  consists  of one of the keywords 'poll' or 'skip',
       followed by a server name, followed by server options, followed by  any
       number  of  user  (or username) descriptions, followed by user options.
       Note: the most common cause of syntax errors  is  mixing  up  user  and
       server options or putting user options before the user descriptions.
       For backward compatibility, the word 'server' is a synonym for 'poll'.
       You  can  use  the  noise  keywords  'and', 'with', 'has', 'wants', and
       'options' anywhere in an entry to make it  resemble  English.   They're
       ignored, but but can make entries much easier to read at a glance.  The
       punctuation characters ':', ';' and ',' are also ignored.
   Poll vs. Skip
       The 'poll' verb tells fetchmail to query this host when it is run  with
       no  arguments.   The  'skip' verb tells fetchmail not to poll this host
       unless it is explicitly named on the command line.   (The  'skip'  verb
       allows  you  to  experiment with test entries safely, or easily disable
       entries for hosts that are temporarily down.)
   Keyword/Option Summary
       Here are the legal options.  Keyword suffixes enclosed in square brack-
       ets  are  optional.   Those corresponding to short command-line options
       are followed by '-' and the appropriate option letter.   If  option  is
       only  relevant to a single mode of operation, it is noted as 's' or 'm'
       for singledrop- or multidrop-mode, respectively.
       Here are the legal global options:

       Keyword             Opt   Mode   Function
       --------------------------------------------------------------------
       set daemon          -d           Set a background poll interval  in
                                        seconds.
       set postmaster                   Give  the  name of the last-resort
                                        mail recipient (default: user run-
                                        ning  fetchmail,  "postmaster"  if
                                        run by the root user)
       set    bouncemail                Direct error mail  to  the  sender
                                        (default)
       set no bouncemail                Direct  error  mail  to  the local
                                        postmaster (as per  the  'postmas-
                                        ter' global option above).
       set no spambounce                Do  not  bounce  spam-blocked mail
                                        (default).
       set    spambounce                Bounce blocked  spam-blocked  mail
                                        (as   per   the   'antispam'  user
                                        option) back to the destination as
                                        indicated   by   the  'bouncemail'
                                        global option.   Warning:  Do  not
                                        use  this  to  bounce spam back to
                                        the sender -  most  spam  is  sent
                                        with false sender address and thus
                                        this   option    hurts    innocent
                                        bystanders.
       set no softbounce                Delete  permanently  undeliverable
                                        mail. It  is  recommended  to  use
                                        this  option  if the configuration
                                        has been thoroughly tested.
       set    softbounce                Keep   permanently   undeliverable
                                        mail  as  though a temporary error
                                        had occurred (default).
       set logfile         -L           Name of a file to append error and
                                        status  messages  to.  Only effec-
                                        tive in daemon mode and if  fetch-
                                        mail   detaches.    If  effective,
                                        overrides set syslog.
       set idfile          -i           Name of  the  file  to  store  UID
                                        lists in.
       set    syslog                    Do   error  logging  through  sys-
                                        log(3). May be  overriden  by  set
                                        logfile.
       set no syslog                    Turn  off  error  logging  through
                                        syslog(3). (default)
       set properties                   String value that  is  ignored  by
                                        fetchmail  (may  be used by exten-
                                        sion scripts).
       Here are the legal server options:

       Keyword          Opt   Mode   Function
       -----------------------------------------------------------------
       via                           Specify DNS  name  of  mailserver,
                                     overriding poll name
       proto[col]       -p           Specify  protocol  (case  insensi-
                                     tive):  POP2,  POP3,  IMAP,  APOP,
                                     KPOP
       local[domains]         m      Specify  domain(s)  to be regarded
                                     as local
       port                          Specify TCP/IP service port (obso-
                                     lete, use 'service' instead).
       service          -P           Specify  service  name  (a numeric
                                     value is also allowed and  consid-
                                     ered a TCP/IP port number).
       auth[enticate]                Set  authentication  type (default
                                     'any')
       timeout          -t           Server inactivity timeout in  sec-
                                     onds (default 300)
       envelope         -E    m      Specify   envelope-address  header
                                     name
       no envelope            m      Disable   looking   for   envelope
                                     address
       qvirtual         -Q    m      Qmail  virtual  domain  prefix  to
                                     remove from user name
       aka                    m      Specify  alternate  DNS  names  of
                                     mailserver
       interface        -I           specify  IP interface(s) that must
                                     be up  for  server  poll  to  take
                                     place
       monitor          -M           Specify  IP address to monitor for
                                     activity
       plugin                        Specify command through  which  to
                                     make server connections.
       plugout                       Specify  command  through which to
                                     make listener connections.
       dns                    m      Enable DNS  lookup  for  multidrop
                                     (default)
       no dns                 m      Disable DNS lookup for multidrop
       checkalias             m      Do  comparison  by  IP address for
                                     multidrop
       no checkalias          m      Do comparison  by  name  for  mul-
                                     tidrop (default)
       uidl             -U           Force   POP3  to  use  client-side
                                     UIDLs (recommended)
       no uidl                       Turn off POP3 use  of  client-side
                                     UIDLs (default)
       interval                      Only  check this site every N poll
                                     cycles; N is a numeric argument.
       tracepolls                    Add poll  tracing  information  to
                                     the Received header
       principal                     Set  Kerberos principal (only use-
                                     ful with IMAP and kerberos)
       esmtpname                     Set name for  RFC2554  authentica-
                                     tion to the ESMTP server.
       esmtppassword                 Set password for RFC2554 authenti-
                                     cation to the ESMTP server.
       bad-header                    How to treat messages with  a  bad
                                     header. Can be reject (default) or
                                     accept.
       Here are the legal user descriptions and options:

       Keyword            Opt   Mode   Function
       -------------------------------------------------------------------
       user[name]         -u           This is the user  description  and
                                       must   come   first  after  server
                                       description  and  after   possible
                                       server  options,  and  before user
                                       options.
                                       It sets the remote user name if by
                                       itself  or followed by 'there', or
                                       the local user name if followed by
                                       'here'.

       is                              Connect   local  and  remote  user
                                       names
       to                              Connect  local  and  remote   user
                                       names
       pass[word]                      Specify remote account password
       ssl                             Connect  to server over the speci-
                                       fied  base  protocol   using   SSL
                                       encryption
       sslcert                         Specify  file for client side pub-
                                       lic SSL certificate
       sslcertfile                     Specify file with trusted CA  cer-
                                       tificates
       sslcertpath                     Specify c_rehash-ed directory with
                                       trusted CA certificates.
       sslkey                          Specify file for client side  pri-
                                       vate SSL key
       sslproto                        Force ssl protocol for connection
       folder             -r           Specify remote folder to query
       smtphost           -S           Specify smtp host(s) to forward to
       fetchdomains             m      Specify  domains  for  which  mail
                                       should be fetched
       smtpaddress        -D           Specify the domain to  be  put  in
                                       RCPT TO lines
       smtpname                        Specify  the user and domain to be
                                       put in RCPT TO lines
       antispam           -Z           Specify  what  SMTP  returns   are
                                       interpreted as spam-policy blocks
       mda                -m           Specify MDA for local delivery
       bsmtp                           Specify BSMTP batch file to append
                                       to
       preconnect                      Command to be executed before each
                                       connection
       postconnect                     Command  to be executed after each
                                       connection
       keep               -k           Don't delete  seen  messages  from
                                       server  (for  POP3, uidl is recom-
                                       mended)
       flush              -F           Flush  all  seen  messages  before
                                       querying (DANGEROUS)
       limitflush                      Flush   all   oversized   messages
                                       before querying
       fetchall           -a           Fetch all messages whether seen or
                                       not
       rewrite                         Rewrite  destination addresses for
                                       reply (default)
       stripcr                         Strip carriage returns  from  ends
                                       of lines
       forcecr                         Force  carriage returns at ends of
                                       lines
       pass8bits                       Force BODY=8BITMIME to ESMTP  lis-
                                       tener
       dropstatus                      Strip  Status and X-Mozilla-Status
                                       lines out of incoming mail
       dropdelivered                   Strip Delivered-To  lines  out  of
                                       incoming mail
       mimedecode                      Convert  quoted-printable to 8-bit
                                       in MIME messages
       idle                            Idle  waiting  for  new   messages
                                       after each poll (IMAP only)
       no keep            -K           Delete  seen  messages from server
                                       (default)
       no flush                        Don't  flush  all  seen   messages
                                       before querying (default)
       no fetchall                     Retrieve    only    new   messages
                                       (default)
       no rewrite                      Don't rewrite headers
       no stripcr                      Don't   strip   carriage   returns
                                       (default)
       no forcecr                      Don't  force  carriage  returns at
                                       EOL (default)
       no pass8bits                    Don't force BODY=8BITMIME to ESMTP
                                       listener (default)
       no dropstatus                   Don't    drop    Status    headers
                                       (default)

       no dropdelivered                Don't  drop  Delivered-To  headers
                                       (default)
       no mimedecode                   Don't  convert quoted-printable to
                                       8-bit in MIME messages (default)
       no idle                         Don't idle waiting  for  new  mes-
                                       sages after each poll (IMAP only)
       limit              -l           Set message size limit
       warnings           -w           Set message size warning interval
       batchlimit         -b           Max  # messages to forward in sin-
                                       gle connect
       fetchlimit         -B           Max # messages to fetch in  single
                                       connect
       fetchsizelimit                  Max  #  message  sizes to fetch in
                                       single transaction
       fastuidl                        Use binary search for first unseen
                                       message (POP3 only)
       expunge            -e           Perform  an  expunge  on every #th
                                       message (IMAP and POP3 only)
       properties                      String value is ignored by  fetch-
                                       mail  (may  be  used  by extension
                                       scripts)
       All user options must begin with a user description (user  or  username
       option) and follow all server descriptions and options.
       In  the  .fetchmailrc  file, the 'envelope' string argument may be pre-
       ceded by a whitespace-separated number.  This number, if specified,  is
       the  number  of  such  headers  to skip over (that is, an argument of 1
       selects the second header of the given type).  This is sometime  useful
       for  ignoring bogus envelope headers created by an ISP's local delivery
       agent or  internal  forwards  (through  mail  inspection  systems,  for
       instance).
   Keywords Not Corresponding To Option Switches
       The  'folder' and 'smtphost' options (unlike their command-line equiva-
       lents) can take a space- or comma-separated  list  of  names  following
       them.
       All  options  correspond  to the obvious command-line arguments, except
       the following: 'via', 'interval', 'aka', 'is',  'to',  'dns'/'no  dns',
       'checkalias'/'no  checkalias', 'password', 'preconnect', 'postconnect',
       'localdomains',   'stripcr'/'no   stripcr',   'forcecr'/'no   forcecr',
       'pass8bits'/'no   pass8bits'  'dropstatus/no  dropstatus',  'dropdeliv-
       ered/no dropdelivered', 'mimedecode/no mimedecode', 'no idle', and  'no
       envelope'.
       The 'via' option is for if you want to have more than one configuration
       pointing at the same site.  If it is present, the string argument  will
       be  taken as the actual DNS name of the mailserver host to query.  This
       will override the argument of poll, which can then simply be a distinct
       label  for  the  configuration (e.g. what you would give on the command
       line to explicitly query this host).
       The 'interval' option (which takes a numeric argument)  allows  you  to
       poll a server less frequently than the basic poll interval.  If you say
       'interval N' the server this option is attached to will only be queried
       every N poll intervals.
   Singledrop vs. Multidrop options
       Please  ensure  you  read  the section titled THE USE AND ABUSE OF MUL-
       TIDROP MAILBOXES if you intend to use multidrop mode.
       The 'is' or  'to'  keywords  associate  the  following  local  (client)
       name(s)  (or  server-name  to client-name mappings separated by =) with
       the mailserver user name in the entry.  If an is/to list has '*' as its
       last  name,  unrecognized  names  are  simply passed through. Note that
       until fetchmail version 6.3.4 inclusively, these lists could only  con-
       tain  local  parts of user names (fetchmail would only look at the part
       before the @ sign). fetchmail versions 6.3.5  and  newer  support  full
       addresses on the left hand side of these mappings, and they take prece-
       dence over any 'localdomains', 'aka', 'via' or similar mappings.
       A single local name can be used to support redirecting your  mail  when
       your  username on the client machine is different from your name on the
       mailserver.  When there is only a single local name, mail is  forwarded
       to  that  local  username regardless of the message's Received, To, Cc,
       and Bcc headers.  In this case, fetchmail never does DNS lookups.
       When there is more than one local name  (or  name  mapping),  fetchmail
       looks  at  the  envelope  header,  if  configured, and otherwise at the
       Received, To, Cc, and Bcc headers of retrieved mail (this is 'multidrop
       mode').   It  looks  for  addresses with hostname parts that match your
       poll name or your 'via', 'aka' or 'localdomains' options,  and  usually
       also  for  hostname  parts  which  DNS  tells  it  are  aliases  of the
       mailserver.  See the discussion of 'dns', 'checkalias', 'localdomains',
       and 'aka' for details on how matching addresses are handled.
       If  fetchmail  cannot  match  any  mailserver  usernames or localdomain
       addresses, the mail will be bounced.  Normally it will  be  bounced  to
       the sender, but if the 'bouncemail' global option is off, the mail will
       go to the local  postmaster  instead.   (see  the  'postmaster'  global
       option). See also BUGS.
       The  'dns'  option  (normally  on) controls the way addresses from mul-
       tidrop mailboxes are checked.  On, it enables logic to check each  host
       address  that  does not match an 'aka' or 'localdomains' declaration by
       looking it up with DNS.   When  a  mailserver  username  is  recognized
       attached to a matching hostname part, its local mapping is added to the
       list of local recipients.
       The 'checkalias' option (normally off) extends the lookups performed by
       the  'dns'  keyword  in  multidrop  mode,  providing a way to cope with
       remote MTAs that identify themselves using their canonical name,  while
       they're polled using an alias.  When such a server is polled, checks to
       extract the envelope address fail, and fetchmail  reverts  to  delivery
       using   the   To/Cc/Bcc   headers   (See  below  'Header  vs.  Envelope
       addresses').  Specifying this option instructs  fetchmail  to  retrieve
       all  the  IP  addresses associated with both the poll name and the name
       used by the remote MTA and to do a  comparison  of  the  IP  addresses.
       This  comes  in  handy  in situations where the remote server undergoes
       frequent canonical name changes, that would otherwise require modifica-
       tions  to the rcfile.  'checkalias' has no effect if 'no dns' is speci-
       fied in the rcfile.
       The 'aka' option is for use with multidrop mailboxes.  It allows you to
       pre-declare  a  list of DNS aliases for a server.  This is an optimiza-
       tion hack that allows you to trade space for  speed.   When  fetchmail,
       while  processing  a multidrop mailbox, grovels through message headers
       looking for names of the mailserver, pre-declaring common ones can save
       it  from  having  to do DNS lookups.  Note: the names you give as argu-
       ments to 'aka' are matched as suffixes -- if  you  specify  (say)  'aka
       netaxs.com',  this  will  match not just a hostname netaxs.com, but any
       hostname that ends with '.netaxs.com'; such  as  (say)  pop3.netaxs.com
       and mail.netaxs.com.
       The 'localdomains' option allows you to declare a list of domains which
       fetchmail should consider local.  When  fetchmail  is  parsing  address
       lines in multidrop modes, and a trailing segment of a host name matches
       a declared local domain, that address is passed through to the listener
       or MDA unaltered (local-name mappings are not applied).
       If you are using 'localdomains', you may also need to specify 'no enve-
       lope', which disables fetchmail's normal attempt to deduce an  envelope
       address  from  the  Received  line  or X-Envelope-To header or whatever
       header has been previously set by 'envelope'.  If you set 'no envelope'
       in the defaults entry it is possible to undo that in individual entries
       by using 'envelope <string>'.  As a special case, 'envelope "Received"'
       restores the default parsing of Received lines.
       The  password  option requires a string argument, which is the password
       to be used with the entry's server.
       The 'preconnect' keyword allows you to specify a shell  command  to  be
       executed  just before each time fetchmail establishes a mailserver con-
       nection.  This may be useful if you are attempting to set up secure POP
       connections  with  the aid of ssh(1).  If the command returns a nonzero
       status, the poll of that mailserver will be aborted.
       Similarly, the 'postconnect' keyword similarly allows you to specify  a
       shell  command to be executed just after each time a mailserver connec-
       tion is taken down.
       The 'forcecr' option controls whether lines terminated by LF  only  are
       given  CRLF  termination  before  forwarding.  Strictly speaking RFC821
       requires this, but few MTAs enforce the requirement it so  this  option
       is  normally  off  (only  one such MTA, qmail, is in significant use at
       time of writing).
       The 'stripcr' option controls whether carriage returns are stripped out
       of retrieved mail before it is forwarded.  It is normally not necessary
       to set this, because it defaults to 'on' (CR  stripping  enabled)  when
       there  is  an  MDA declared but 'off' (CR stripping disabled) when for-
       warding is via SMTP.  If 'stripcr' and 'forcecr' are both on, 'stripcr'
       will override.
       The 'pass8bits' option exists to cope with Microsoft mail programs that
       stupidly slap a "Content-Transfer-Encoding: 7bit" on everything.   With
       this  option  off  (the  default)  and such a header present, fetchmail
       declares BODY=7BIT to an ESMTP-capable listener; this  causes  problems
       for  messages  actually  using 8-bit ISO or KOI-8 character sets, which
       will be garbled by having the high bits of all characters stripped.  If
       'pass8bits'  is on, fetchmail is forced to declare BODY=8BITMIME to any
       ESMTP-capable listener.  If the listener is  8-bit-clean  (as  all  the
       major ones now are) the right thing will probably result.
       The 'dropstatus' option controls whether nonempty Status and X-Mozilla-
       Status lines are retained in fetched mail (the default)  or  discarded.
       Retaining  them  allows  your  MUA  to  see what messages (if any) were
       marked seen on the server.  On the other hand, it can confuse some new-
       mail notifiers, which assume that anything with a Status line in it has
       been seen.  (Note: the empty Status lines inserted by  some  buggy  POP
       servers are unconditionally discarded.)
       The  'dropdelivered'  option controls whether Delivered-To headers will
       be kept in fetched mail (the default) or discarded. These  headers  are
       added by Qmail and Postfix mailservers in order to avoid mail loops but
       may get in your way if you try to "mirror" a mailserver within the same
       domain. Use with caution.
       The  'mimedecode'  option  controls  whether  MIME  messages  using the
       quoted-printable encoding are automatically converted into  pure  8-bit
       data.  If you are delivering mail to an ESMTP-capable, 8-bit-clean lis-
       tener (that includes all of the major MTAs like  sendmail),  then  this
       will  automatically  convert  quoted-printable message headers and data
       into 8-bit data, making it easier to understand when reading  mail.  If
       your  e-mail  programs  know  how to deal with MIME messages, then this
       option is not needed.  The mimedecode option is off by default, because
       doing  RFC2047 conversion on headers throws away character-set informa-
       tion and can lead to bad results if the encoding of the headers differs
       from the body encoding.
       The  'idle'  option is intended to be used with IMAP servers supporting
       the RFC2177 IDLE command extension, but does not strictly  require  it.
       If it is enabled, and fetchmail detects that IDLE is supported, an IDLE
       will be issued at the end of each poll.  This will tell the IMAP server
       to  hold  the  connection  open  and notify the client when new mail is
       available.  If IDLE is not supported, fetchmail  will  simulate  it  by
       periodically  issuing NOOP. If you need to poll a link frequently, IDLE
       can save bandwidth by  eliminating  TCP/IP  connects  and  LOGIN/LOGOUT
       sequences. On the other hand, an IDLE connection will eat almost all of
       your fetchmail's time, because it will never drop  the  connection  and
       allow  other  polls  to occur unless the server times out the IDLE.  It
       also doesn't work with multiple folders; only  the  first  folder  will
       ever be polled.

       The  'properties'  option is an extension mechanism.  It takes a string
       argument, which is ignored by fetchmail itself.   The  string  argument
       may  be  used  to  store  configuration  information  for scripts which
       require it.  In particular, the output of  '--configdump'  option  will
       make  properties  associated  with  a user entry readily available to a
       Python script.
   Miscellaneous Run Control Options
       The words 'here' and 'there'  have  useful  English-like  significance.
       Normally  'user  eric  is esr' would mean that mail for the remote user
       'eric' is to be delivered to 'esr', but you can make  this  clearer  by
       saying 'user eric there is esr here', or reverse it by saying 'user esr
       here is eric there'
       Legal protocol identifiers for use with the 'protocol' keyword are:
           auto (or AUTO) (legacy, to be removed from future release)
           pop2 (or POP2) (legacy, to be removed from future release)
           pop3 (or POP3)
           sdps (or SDPS)
           imap (or IMAP)
           apop (or APOP)
           kpop (or KPOP)

       Legal authentication types are  'any',  'password',  'kerberos',  'ker-
       beros_v4',  'kerberos_v5'  and 'gssapi', 'cram-md5', 'otp', 'msn' (only
       for POP3), 'ntlm', 'ssh', 'external' (only IMAP).  The 'password'  type
       specifies  authentication  by  normal  transmission  of a password (the
       password may be plain text or subject to  protocol-specific  encryption
       as  in  CRAM-MD5);  'kerberos' tells fetchmail to try to get a Kerberos
       ticket at the start of each query instead, and send an arbitrary string
       as the password; and 'gssapi' tells fetchmail to use GSSAPI authentica-
       tion.  See the description of the 'auth' keyword for more.
       Specifying 'kpop' sets POP3 protocol over port 1109  with  Kerberos  V4
       authentication.  These defaults may be overridden by later options.
       There  are  some  global option statements: 'set logfile' followed by a
       string sets the same global specified  by  --logfile.   A  command-line
       --logfile option will override this. Note that --logfile is only effec-
       tive if fetchmail detaches itself from the  terminal  and  the  logfile
       already  exists  before  fetchmail is run, and it overrides --syslog in
       this case.  Also, 'set daemon' sets the poll interval as --daemon does.
       This can be overridden by a command-line --daemon option; in particular
       --daemon 0 can be used to force foreground operation. The 'set postmas-
       ter'  statement  sets  the  address to which multidrop mail defaults if
       there are no local matches.  Finally, 'set syslog' sends  log  messages
       to syslogd(8).

DEBUGGING FETCHMAIL
   Fetchmail crashing
       There are various ways in that fetchmail may "crash", i. e. stop opera-
       tion suddenly and unexpectedly. A "crash" usually refers  to  an  error
       condition  that  the  software  did  not handle by itself. A well-known
       failure mode is the "segmentation fault" or "signal 11" or "SIGSEGV" or
       just  "segfault" for short. These can be caused by hardware or by soft-
       ware problems. Software-induced segfaults  can  usually  be  reproduced
       easily and in the same place, whereas hardware-induced segfaults can go
       away if the computer is rebooted, or powered off for a few  hours,  and
       can  happen  in  random locations even if you use the software the same
       way.
       For solving hardware-induced segfaults, find the faulty  component  and
       repair  or  replace it.  The Sig11 FAQ <http://www.bitwizard.nl/sig11/>;
       may help you with details.
       For solving software-induced  segfaults,  the  developers  may  need  a
       "stack backtrace".

   Enabling fetchmail core dumps
       By  default,  fetchmail  suppresses  core  dumps as these might contain
       passwords and other  sensitive  information.  For  debugging  fetchmail
       crashes,  obtaining  a  "stack backtrace" from a core dump is often the
       quickest way to solve the problem, and when posting your problem  on  a
       mailing list, the developers may ask you for a "backtrace".
       1.  To  get  useful backtraces, fetchmail needs to be installed without
       getting stripped  of  its  compilation  symbols.   Unfortunately,  most
       binary  packages  that  are installed are stripped, and core files from
       symbol-stripped programs are worthless. So you may  need  to  recompile
       fetchmail. On many systems, you can type
               file `which fetchmail`
       to  find  out  if  fetchmail  was  symbol-stripped or not. If yours was
       unstripped, fine, proceed, if it was stripped, you  need  to  recompile
       the  source code first. You do not usually need to install fetchmail in
       order to debug it.
       2. The shell environment that starts fetchmail  needs  to  enable  core
       dumps.  The  key  is the "maximum core (file) size" that can usually be
       configured with a tool named "limit" or "ulimit". See the documentation
       for  your  shell  for  details.  In the popular bash shell, "ulimit -Sc
       unlimited" will allow the core dump.
       3. You need to tell fetchmail, too, to allow core dumps.  To  do  this,
       run  fetchmail with the -d0 -v options.  It is often easier to also add
       --nosyslog -N as well.
       Finally, you need to reproduce the crash. You can just start  fetchmail
       from  the directory where you compiled it by typing ./fetchmail, so the
       complete command line will start with ./fetchmail -Nvd0 --nosyslog  and
       perhaps list your other options.
       After the crash, run your debugger to obtain the core dump.  The debug-
       ger will often be GNU GDB, you can then type (adjust  paths  as  neces-
       sary) gdb ./fetchmail fetchmail.core and then, after GDB has started up
       and read all its files, type backtrace full, save the  output  (copy  &
       paste  will  do,  the  backtrace will be read by a human) and then type
       quit to leave gdb.  Note: on some systems, the core files have  differ-
       ent  names, they might contain a number instead of the program name, or
       number and name, but it will usually have "core" as part of their name.

INTERACTION WITH RFC 822
       When trying to determine the originating address of a  message,  fetch-
       mail looks through headers in the following order:
               Return-Path:
               Resent-Sender: (ignored if it doesn't contain an @ or !)
               Sender: (ignored if it doesn't contain an @ or !)
               Resent-From:
               From:
               Reply-To:
               Apparently-From:
       The  originating  address is used for logging, and to set the MAIL FROM
       address when forwarding to SMTP.  This order is intended to cope grace-
       fully  with  receiving  mailing  list  messages  in multidrop mode. The
       intent is that if a local address doesn't  exist,  the  bounce  message
       won't  be  returned  blindly  to  the author or to the list itself, but
       rather to the list manager (which is less annoying).
       In multidrop mode, destination headers are processed as follows: First,
       fetchmail  looks  for  the header specified by the 'envelope' option in
       order to  determine  the  local  recipient  address.  If  the  mail  is
       addressed  to  more than one recipient, the Received line won't contain
       any information regarding recipient addresses.
       Then fetchmail looks for the Resent-To:,  Resent-Cc:,  and  Resent-Bcc:
       lines.   If  they  exist,  they should contain the final recipients and
       have precedence over their To:/Cc:/Bcc: counterparts.  If the  Resent-*
       lines  don't  exist,  the  To:,  Cc:, Bcc: and Apparently-To: lines are
       looked for. (The presence of a Resent-To: is taken to  imply  that  the
       person  referred  by  the To: address has already received the original
       copy of the mail.)

CONFIGURATION EXAMPLES
       Note that although there are password declarations in a  good  many  of
       the  examples below, this is mainly for illustrative purposes.  We rec-
       ommend stashing account/password pairs in your $HOME/.netrc file, where
       they  can  be  used  not just by fetchmail but by ftp(1) and other pro-
       grams.
       The basic format is:

              poll SERVERNAME protocol PROTOCOL username NAME  password  PASS-
              WORD

       Example:

              poll pop.provider.net protocol pop3 username "jsmith" password "secret1"

       Or, using some abbreviations:

              poll pop.provider.net proto pop3 user "jsmith" password "secret1"

       Multiple servers may be listed:

              poll pop.provider.net proto pop3 user "jsmith" pass "secret1"
              poll other.provider.net proto pop2 user "John.Smith" pass "My^Hat"

       Here's the same version with more whitespace and some noise words:

              poll pop.provider.net proto pop3
                   user "jsmith", with password secret1, is "jsmith" here;
              poll other.provider.net proto pop2:
                   user "John.Smith", with password "My^Hat", is "John.Smith" here;

       If  you  need  to include whitespace in a parameter string or start the
       latter with a number, enclose the string in double quotes.  Thus:

              poll mail.provider.net with proto pop3:
                   user "jsmith" there has password "4u but u can't krak this"
                   is jws here and wants mda "/bin/mail"

       You may have an  initial  server  description  headed  by  the  keyword
       'defaults'  instead  of  'poll'  followed  by a name.  Such a record is
       interpreted as defaults for all queries to use. It may  be  overwritten
       by individual server descriptions.  So, you could write:

              defaults proto pop3
                   user "jsmith"
              poll pop.provider.net
                   pass "secret1"
              poll mail.provider.net
                   user "jjsmith" there has password "secret2"

       It's  possible  to  specify  more than one user per server.  The 'user'
       keyword leads off a user description, and every user specification in a
       multi-user entry must include it.  Here's an example:

              poll pop.provider.net proto pop3 port 3111
                   user "jsmith" with pass "secret1" is "smith" here
                   user jones with pass "secret2" is "jjones" here keep

       This  associates  the  local username 'smith' with the pop.provider.net
       username  'jsmith'  and  the   local   username   'jjones'   with   the
       pop.provider.net  username  'jones'.   Mail  for 'jones' is kept on the
       server after download.

       Here's what a simple retrieval configuration for  a  multidrop  mailbox
       looks like:

              poll pop.provider.net:
                   user maildrop with pass secret1 to golux 'hurkle'='happy' snark here

       This  says  that  the  mailbox of account 'maildrop' on the server is a
       multidrop box, and that messages in it should be parsed for the  server
       user  names  'golux', 'hurkle', and 'snark'.  It further specifies that
       'golux' and 'snark' have the same name on the client as on the  server,
       but  mail  for  server user 'hurkle' should be delivered to client user
       'happy'.

       Note  that  fetchmail,  until  version  6.3.4,  did  NOT   allow   full
       user@domain  specifications  here,  these would never match.  Fetchmail
       6.3.5 and newer support user@domain  specifications  on  the  left-hand
       side of a user mapping.

       Here's an example of another kind of multidrop connection:

              poll pop.provider.net localdomains loonytoons.org toons.org
                   envelope X-Envelope-To
                   user maildrop with pass secret1 to * here

       This  also says that the mailbox of account 'maildrop' on the server is
       a multidrop box.  It tells fetchmail that any  address  in  the  loony-
       toons.org  or  toons.org  domains  (including sub-domain addresses like
       'joe AT daffy.org') should be passed through to the local  SMTP
       listener  without  modification.   Be  careful  of mail loops if you do
       this!

       Here's an example configuration using ssh and the plugin  option.   The
       queries  are  made  directly  on the stdin and stdout of imapd via ssh.
       Note that in this setup, IMAP authentication can be skipped.

              poll mailhost.net with proto imap:
                   plugin "ssh %h /usr/sbin/imapd" auth ssh;
                   user esr is esr here

THE USE AND ABUSE OF MULTIDROP MAILBOXES
       Use the multiple-local-recipients feature with caution -- it can  bite.
       All multidrop features are ineffective in ETRN and ODMR modes.
       Also,  note  that  in multidrop mode duplicate mails are suppressed.  A
       piece of mail is considered duplicate if it has the same message-ID  as
       the  message  immediately  preceding and more than one addressee.  Such
       runs of messages may be generated when copies of a message addressed to
       multiple users are delivered to a multidrop box.

   Header vs. Envelope addresses
       The  fundamental problem is that by having your mailserver toss several
       peoples' mail in a single maildrop box, you may have thrown away poten-
       tially  vital  information  about  who  each piece of mail was actually
       addressed  to  (the  'envelope  address',  as  opposed  to  the  header
       addresses in the RFC822 To/Cc headers - the Bcc is not available at the
       receiving end).  This 'envelope address' is the  address  you  need  in
       order to reroute mail properly.
       Sometimes fetchmail can deduce the envelope address.  If the mailserver
       MTA is sendmail and the item of mail had just one  recipient,  the  MTA
       will  have  written a 'by/for' clause that gives the envelope addressee
       into its Received header. But this  doesn't  work  reliably  for  other
       MTAs,  nor  if there is more than one recipient.  By default, fetchmail
       looks for envelope addresses in  these  lines;  you  can  restore  this
       default with -E "Received" or 'envelope Received'.
       As a better alternative, some SMTP listeners and/or mail servers insert
       a header in each message containing a copy of the  envelope  addresses.
       This  header  (when it exists) is often 'X-Original-To', 'Delivered-To'
       or 'X-Envelope-To'.  Fetchmail's assumption about this can  be  changed
       with the -E or 'envelope' option.  Note that writing an envelope header
       of this kind exposes the  names  of  recipients  (including  blind-copy
       recipients)  to  all  receivers  of  the messages, so the upstream must
       store one copy of the message per recipient to avoid becoming a privacy
       problem.
       Postfix,  since version 2.0, writes an X-Original-To: header which con-
       tains a copy of the envelope as it was received.
       Qmail and Postfix generally write a 'Delivered-To' header upon deliver-
       ing  the  message  to  the  mail  spool and use it to avoid mail loops.
       Qmail virtual domains however will prefix the user name with  a  string
       that  normally matches the user's domain. To remove this prefix you can
       use the -Q or 'qvirtual' option.
       Sometimes, unfortunately, neither of these methods works.  That is  the
       point  when you should contact your ISP and ask them to provide such an
       envelope header, and you should not use multidrop  in  this  situation.
       When  they  all fail, fetchmail must fall back on the contents of To/Cc
       headers (Bcc headers are not available - see below) to try to determine
       recipient addressees -- and these are unreliable.  In particular, mail-
       ing-list software often ships mail with only the list broadcast address
       in the To header.
       Note that a future version of fetchmail may remove To/Cc parsing!
       When fetchmail cannot deduce a recipient address that is local, and the
       intended recipient address was anyone other than  fetchmail's  invoking
       user,  mail  will  get  lost.  This is what makes the multidrop feature
       risky without proper envelope information.
       A related problem is that when you blind-copy a mail message,  the  Bcc
       information  is carried only as envelope address (it's removed from the
       headers by the sending mail server, so fetchmail can  see  it  only  if
       there  is an X-Envelope-To header).  Thus, blind-copying to someone who
       gets mail over a fetchmail multidrop link  will  fail  unless  the  the
       mailserver  host routinely writes X-Envelope-To or an equivalent header
       into messages in your maildrop.
       In conclusion, mailing lists and Bcc'd mail can only work if the server
       you're fetching from
       (1)    stores one copy of the message per recipient in your domain and
       (2)    records  the  envelope information in a special header (X-Origi-
              nal-To, Delivered-To, X-Envelope-To).

   Good Ways To Use Multidrop Mailboxes
       Multiple local names can be used to administer a mailing list from  the
       client side of a fetchmail collection.  Suppose your name is 'esr', and
       you want to both pick up your own mail  and  maintain  a  mailing  list
       called  (say)  "fetchmail-friends", and you want to keep the alias list
       on your client machine.
       On your server, you can alias 'fetchmail-friends' to  'esr';  then,  in
       your .fetchmailrc, declare 'to esr fetchmail-friends here'.  Then, when
       mail including 'fetchmail-friends' as a local address gets fetched, the
       list name will be appended to the list of recipients your SMTP listener
       sees.  Therefore it will undergo alias expansion locally.  Be  sure  to
       include  'esr'  in  the  local alias expansion of fetchmail-friends, or
       you'll never see mail sent only to the list.  Also be  sure  that  your
       listener  has  the  "me-too"  option  set (sendmail's -oXm command-line
       option or OXm declaration) so your name isn't removed from alias expan-
       sions in messages you send.
       This  trick  is not without its problems, however.  You'll begin to see
       this when a message comes in that is addressed only to a  mailing  list
       you  do not have declared as a local name.  Each such message will fea-
       ture an 'X-Fetchmail-Warning' header which is generated because  fetch-
       mail  cannot  find a valid local name in the recipient addresses.  Such
       messages default (as was described above) to being sent  to  the  local
       user  running fetchmail, but the program has no way to know that that's
       actually the right thing.

   Bad Ways To Abuse Multidrop Mailboxes
       Multidrop mailboxes and fetchmail serving multiple users in daemon mode
       do not mix.  The problem, again, is mail from mailing lists, which typ-
       ically does not have an individual recipient address  on  it.    Unless
       fetchmail can deduce an envelope address, such mail will only go to the
       account running fetchmail (probably root).   Also,  blind-copied  users
       are very likely never to see their mail at all.
       If  you're tempted to use fetchmail to retrieve mail for multiple users
       from a single mail drop via POP or IMAP, think again  (and  reread  the
       section  on  header and envelope addresses above).  It would be smarter
       to just let the mail sit in the mailserver's queue and use  fetchmail's
       ETRN  or ODMR modes to trigger SMTP sends periodically (of course, this
       means you have to poll more frequently  than  the  mailserver's  expiry
       period).  If you can't arrange this, try setting up a UUCP feed.
       If  you  absolutely must use multidrop for this purpose, make sure your
       mailserver writes an envelope-address header that  fetchmail  can  see.
       Otherwise you will lose mail and it will come back to haunt you.

   Speeding Up Multidrop Checking
       Normally, when multiple users are declared fetchmail extracts recipient
       addresses as described above and checks each host part with DNS to  see
       if it's an alias of the mailserver.  If so, the name mappings described
       in the "to ... here" declaration are done and the mail  locally  deliv-
       ered.
       This is a convenient but also slow method.  To speed it up, pre-declare
       mailserver aliases with 'aka'; these are checked before DNS lookups are
       done.   If you're certain your aka list contains all DNS aliases of the
       mailserver (and all MX names pointing at it - note this may change in a
       future  version)  you  can  declare  'no  dns'  to suppress DNS lookups
       entirely and only match against the aka list.

SOCKS
       Support for socks4/5 is a compile time configuration option. Once  com-
       piled  in, fetchmail will always use the socks libraries and configura-
       tion on your system, there are no run-time switches in fetchmail -  but
       you  can  still configure SOCKS: you can specify which SOCKS configura-
       tion file is used in the SOCKS_CONF environment variable.
       For instance, if you wanted to bypass the SOCKS  proxy  altogether  and
       have    fetchmail    connect    directly,    you    could   just   pass
       SOCKS_CONF=/dev/null in the environment, for example  (add  your  usual
       command line options - if any - to the end of this line):
       env SOCKS_CONF=/dev/null fetchmail

EXIT CODES
       To  facilitate  the  use  of fetchmail in shell scripts, an exit status
       code is returned to give an indication of what occurred during a  given
       connection.
       The exit codes returned by fetchmail are as follows:
       0      One  or more messages were successfully retrieved (or, if the -c
              option was selected, were found waiting but not retrieved).
       1      There was no mail awaiting retrieval.  (There may have been  old
              mail still on the server but not selected for retrieval.) If you
              do not want "no mail" to be an error  condition  (for  instance,
              for cron jobs), use a POSIX-compliant shell and add
              || [ $? -eq 1 ]
              to  the end of the fetchmail command line, note that this leaves
              0 untouched, maps 1 to 0, and maps all other  codes  to  1.  See
              also item #C8 in the FAQ.
       2      An  error  was  encountered  when attempting to open a socket to
              retrieve mail.  If you don't know what a socket is, don't  worry
              about  it  -- just treat this as an 'unrecoverable error'.  This
              error can also be because a protocol fetchmail wants to  use  is
              not listed in /etc/services.
       3      The  user authentication step failed.  This usually means that a
              bad user-id, password, or APOP id was specified.  Or it may mean
              that you tried to run fetchmail under circumstances where it did
              not have standard input attached to a  terminal  and  could  not
              prompt for a missing password.
       4      Some sort of fatal protocol error was detected.
       5      There  was  a  syntax  error in the arguments to fetchmail, or a
              pre- or post-connect command failed.
       6      The run control file had bad permissions.
       7      There was an error condition reported by the server.   Can  also
              fire if fetchmail timed out while waiting for the server.
       8      Client-side  exclusion error.  This means fetchmail either found
              another copy of itself already running, or failed in such a  way
              that it isn't sure whether another copy is running.
       9      The user authentication step failed because the server responded
              "lock busy".  Try again after a brief pause!  This error is  not
              implemented  for  all  protocols,  nor  for all servers.  If not
              implemented for your server, "3" will be returned  instead,  see
              above.  May be returned when talking to qpopper or other servers
              that can respond with "lock busy" or some similar text  contain-
              ing the word "lock".
       10     The fetchmail run failed while trying to do an SMTP port open or
              transaction.
       11     Fatal DNS error.  Fetchmail encountered an error while  perform-
              ing a DNS lookup at startup and could not proceed.
       12     BSMTP batch file could not be opened.
       13     Poll terminated by a fetch limit (see the --fetchlimit option).
       14     Server busy indication.
       23     Internal error.  You should see a message on standard error with
              details.
       24 - 26, 28, 29
              These are internal codes and should not appear externally.
       When fetchmail queries more than one host, return status is  0  if  any
       query  successfully retrieved mail. Otherwise the returned error status
       is that of the last host queried.

FILES
       ~/.fetchmailrc
            default run control file
       ~/.fetchids
            default location of file recording  last  message  UIDs  seen  per
            host.
       ~/.fetchmail.pid
            lock file to help prevent concurrent runs (non-root mode).
       ~/.netrc
            your FTP run control file, which (if present) will be searched for
            passwords as a last resort before prompting for one interactively.
       /var/run/fetchmail.pid
            lock file to help prevent concurrent runs (root mode,  Linux  sys-
            tems).
       /etc/fetchmail.pid
            lock  file  to  help  prevent  concurrent runs (root mode, systems
            without /var/run).

ENVIRONMENT
       FETCHMAILHOME
              If this environment variable is set  to  a  valid  and  existing
              directory  name,  fetchmail will read $FETCHMAILHOME/fetchmailrc
              (the dot is missing in this case), $FETCHMAILHOME/.fetchids  and
              $FETCHMAILHOME/.fetchmail.pid  rather  than from the user's home
              directory.  The .netrc file is always  looked  for  in  the  the
              invoking  user's  home  directory  regardless of FETCHMAILHOME's
              setting.

       FETCHMAILUSER
              If this environment variable is set, it is used as the  name  of
              the calling user (default local name) for purposes such as mail-
              ing error notifications.  Otherwise, if either  the  LOGNAME  or
              USER  variable  is  correctly  set  (e.g.  the corresponding UID
              matches the session user ID) then  that  name  is  used  as  the
              default  local  name.   Otherwise  getpwuid(3)  must  be able to
              retrieve a password entry for the  session  ID  (this  elaborate
              logic  is  designed  to  handle  the  case of multiple names per
              userid gracefully).

       FETCHMAIL_DISABLE_CBC_IV_COUNTERMEASURE
              (since v6.3.22): If this environment variable  is  set  and  not
              empty,  fetchmail  will  disable a countermeasure against an SSL
              CBC IV attack (by  setting  SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS).
              This  is a security risk, but may be necessary for connecting to
              certain non-standards-conforming servers.  See fetchmail's  NEWS
              file  and  fetchmail-SA-2012-01.txt for details.  Earlier fetch-
              mail versions (v6.3.21 and older) used to disable this  counter-
              measure, but v6.3.22 no longer does that as a safety precaution.

       FETCHMAIL_INCLUDE_DEFAULT_X509_CA_CERTS
              (since  v6.3.17):  If  this  environment variable is set and not
              empty, fetchmail will always load the default X.509 trusted cer-
              tificate   locations   for  SSL/TLS  CA  certificates,  even  if
              --sslcertfile and --sslcertpath are given.  The latter locations
              take precedence over the system default locations.  This is use-
              ful in case there are broken certificates in the system directo-
              ries  and the user has no administrator privileges to remedy the
              problem.

       HOME_ETC
              If  the  HOME_ETC  variable  is   set,   fetchmail   will   read
              $HOME_ETC/.fetchmailrc instead of ~/.fetchmailrc.
              If  HOME_ETC  and  FETCHMAILHOME  are both set, HOME_ETC will be
              ignored.

       SOCKS_CONF
              (only if SOCKS support is compiled in) this variable is used  by
              the socks library to find out which configuration file it should
              read. Set this to /dev/null to bypass the SOCKS proxy.

SIGNALS
       If a fetchmail daemon is running as root, SIGUSR1 wakes it up from  its
       sleep  phase and forces a poll of all non-skipped servers. For compati-
       bility reasons, SIGHUP can also be used in 6.3.X but may not be  avail-
       able in future fetchmail versions.
       If fetchmail is running in daemon mode as non-root, use SIGUSR1 to wake
       it (this is so SIGHUP due to logout can retain the  default  action  of
       killing it).
       Running fetchmail in foreground while a background fetchmail is running
       will do whichever of these is appropriate to wake it up.

BUGS, LIMITATIONS, AND KNOWN PROBLEMS
       Please check the NEWS file that shipped with fetchmail for  more  known
       bugs than those listed here.
       Fetchmail  cannot  handle  user  names  that contain blanks after a "@"
       character, for instance "demonstr@ti on". These are rather uncommon and
       only  hurt when using UID-based --keep setups, so the 6.3.X versions of
       fetchmail won't be fixed.
       Fetchmail cannot handle configurations where you have multiple accounts
       that  use the same server name and the same login. Any user@server com-
       bination must be unique.
       The assumptions that the DNS and in particular the  checkalias  options
       make  are  not  often sustainable. For instance, it has become uncommon
       for an MX server to be a POP3 or IMAP server at the same  time.  There-
       fore the MX lookups may go away in a future release.
       The  mda  and plugin options interact badly.  In order to collect error
       status from the MDA, fetchmail has to change its normal signal handling
       so  that  dead  plugin  processes don't get reaped until the end of the
       poll cycle.  This can cause resource starvation  if  too  many  zombies
       accumulate.   So  either  don't  deliver to a MDA using plugins or risk
       being overrun by an army of undead.
       The --interface option does not support IPv6 and it is doubtful  if  it
       ever  will,  since  there  is  no  portable way to query interface IPv6
       addresses.
       The RFC822 address  parser  used  in  multidrop  mode  chokes  on  some
       @-addresses  that  are  technically legal but bizarre.  Strange uses of
       quoting and embedded comments are likely to confuse it.
       In a message with multiple envelope headers, only  the  last  one  pro-
       cessed will be visible to fetchmail.
       Use  of  some  of  these protocols requires that the program send unen-
       crypted passwords over the TCP/IP connection to the  mailserver.   This
       creates a risk that name/password pairs might be snaffled with a packet
       sniffer or more sophisticated monitoring  software.   Under  Linux  and
       FreeBSD,  the  --interface  option  can  be used to restrict polling to
       availability of a specific interface device with a  specific  local  or
       remote  IP  address,  but snooping is still possible if (a) either host
       has a network device that can be opened in promiscuous mode, or (b) the
       intervening network link can be tapped.  We recommend the use of ssh(1)
       tunnelling to not only shroud your passwords  but  encrypt  the  entire
       conversation.
       Use  of  the  %F  or  %T escapes in an mda option could open a security
       hole, because they pass text manipulable by an attacker to a shell com-
       mand.  Potential shell characters are replaced by '_' before execution.
       The hole is further reduced by the fact that fetchmail temporarily dis-
       cards any suid privileges it may have while running the MDA.  For maxi-
       mum safety, however, don't use an mda command containing %F or %T  when
       fetchmail is run from the root account itself.
       Fetchmail's  method  of  sending bounces due to errors or spam-blocking
       and spam bounces requires that port 25 of localhost  be  available  for
       sending mail via SMTP.
       If you modify ~/.fetchmailrc while a background instance is running and
       break the syntax, the background instance will die silently.   Unfortu-
       nately,  it  can't die noisily because we don't yet know whether syslog
       should be enabled.  On some systems, fetchmail  dies  quietly  even  if
       there is no syntax error; this seems to have something to do with buggy
       terminal ioctl code in the kernel.
       The -f - option (reading a configuration from  stdin)  is  incompatible
       with the plugin option.
       The 'principal' option only handles Kerberos IV, not V.
       Interactively  entered  passwords are truncated after 63 characters. If
       you really need to use a longer password, you will have to use  a  con-
       figuration file.
       A  backslash  as  the  last  character  of a configuration file will be
       flagged as a syntax error rather than ignored.
       The BSMTP error handling is virtually nonexistent and may leave  broken
       messages behind.
       Send comments, bug reports, gripes, and the like to the fetchmail-devel
       list <fetchmail-devel AT lists.de>

       An HTML FAQ <http://fetchmail.berlios.de/fetchmail-FAQ.html>; is  avail-
       able  at the fetchmail home page, it should also accompany your instal-
       lation.

AUTHOR
       Fetchmail is currently maintained by Matthias Andree and Rob Funk  with
       major  assistance  from  Sunil Shetye (for code) and Rob MacGregor (for
       the mailing lists).
       Most of the code is from Eric S. Raymond <esr AT snark.com> .  Too
       many other people to name here have contributed code and patches.
       This  program  is descended from and replaces popclient, by Carl Harris
       <ceharris AT mal.com> ; the internals have  become  quite  different,  but
       some  of  its  interface design is directly traceable to that ancestral
       program.
       This manual page has been improved by Matthias Andree, R. Hannes  Bein-
       ert, and Hector Garcia.

SEE ALSO
       README, README.SSL, README.SSL-SERVER, The Fetchmail FAQ <http://
       www.fetchmail.info/fetchmail-FAQ.html>, mutt(1), elm(1), mail(1), send-
       mail(8), popd(8), imapd(8), netrc(5).

       The fetchmail home page.  <http://fetchmail.berlios.de/>;

       The maildrop home page.  <http://www.courier-mta.org/maildrop/>;

APPLICABLE STANDARDS
       Note that this list is just a collection of references and not a state-
       ment as to the actual protocol conformance or  requirements  in  fetch-
       mail.
       SMTP/ESMTP:
            RFC  821,  RFC  2821,  RFC 1869, RFC 1652, RFC 1870, RFC 1983, RFC
            1985, RFC 2554.
       mail:
            RFC 822, RFC 2822, RFC 1123, RFC 1892, RFC 1894.
       POP2:
            RFC 937
       POP3:
            RFC 1081, RFC 1225, RFC 1460, RFC 1725, RFC 1734,  RFC  1939,  RFC
            1957, RFC 2195, RFC 2449.
       APOP:
            RFC 1939.
       RPOP:
            RFC 1081, RFC 1225.
       IMAP2/IMAP2BIS:
            RFC 1176, RFC 1732.
       IMAP4/IMAP4rev1:
            RFC  1730,  RFC  1731, RFC 1732, RFC 2060, RFC 2061, RFC 2195, RFC
            2177, RFC 2683.
       ETRN:
            RFC 1985.
       ODMR/ATRN:
            RFC 2645.
       OTP: RFC 1938.
       LMTP:
            RFC 2033.
       GSSAPI:
            RFC 1508, RFC 1734, Generic Security Service Application Program
            Interface (GSSAPI)/Kerberos/Simple Authentication and Security
            Layer (SASL) Service Names <http://www.iana.org/assignments/
            gssapi-service-names/>.
       TLS: RFC 2595.

fetchmail                      fetchmail 6.3.24                   fetchmail(1)