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Mail::DKIM::DNS(3)    User Contributed Perl Documentation   Mail::DKIM::DNS(3)
NAME
       Mail::DKIM::DNS - performs DNS queries for Mail::DKIM
VERSION
       version 1.20200907
DESCRIPTION
       This is the module that performs DNS queries for Mail::DKIM.
CONFIGURATION
       This module has a couple configuration settings that the caller may
       want to use to customize the behavior of this module.
   $Mail::DKIM::DNS::TIMEOUT
       This global variable specifies the maximum amount of time (in seconds)
       to wait for a single DNS query to complete. The default is 10.
   Mail::DKIM::DNS::resolver()
       Use this global subroutine to get or replace the instance of
       Net::DNS::Resolver that Mail::DKIM uses. If set to undef (the default),
       then a brand new default instance of Net::DNS::Resolver will be created
       the first time a DNS query is needed.
       You will call this subroutine if you want to specify non-default
       options to Net::DNS::Resolver, such as different timeouts, or to enable
       use of a persistent socket. For example:
         # first, construct a custom DNS resolver
         my $res = Net::DNS::Resolver->new(
                           udp_timeout => 3, tcp_timeout => 3, retry => 2,
                        );
         $res->udppacketsize(1240);
         $res->persistent_udp(1);
         # then, tell Mail::DKIM to use this resolver
         Mail::DKIM::DNS::resolver($res);
   Mail::DKIM::DNS::enable_EDNS0()
       This is a convenience subroutine that will construct an appropriate DNS
       resolver that uses EDNS0 (Extension mechanisms for DNS) to support
       large DNS replies, and configure Mail::DKIM to use it. (As such, it
       should NOT be used in conjunction with the resolver() subroutine
       described above.)
         Mail::DKIM::DNS::enable_EDNS0();
       Use of EDNS0 is recommended, since it reduces the need for falling back
       to TCP when dealing with large DNS packets. However, it is not enabled
       by default because some Internet firewalls which do deep inspection of
       packets are not able to process EDNS0-enabled packets. When there is a
       firewall on a path to a DNS resolver, the EDNS0 feature should be
       specifically tested before enabling.
AUTHORS
       o   Jason Long <jason AT long.name>
       o   Marc Bradshaw <marc AT marcbradshaw.net>
       o   Bron Gondwana <brong AT fastmailteam.com> (ARC)
THANKS
       Work on ensuring that this module passes the ARC test suite was
       generously sponsored by Valimail (https://www.valimail.com/)
COPYRIGHT AND LICENSE
       o   Copyright (C) 2013 by Messiah College
       o   Copyright (C) 2010 by Jason Long
       o   Copyright (C) 2017 by Standcore LLC
       o   Copyright (C) 2020 by FastMail Pty Ltd
       This library is free software; you can redistribute it and/or modify it
       under the same terms as Perl itself, either Perl version 5.8.6 or, at
       your option, any later version of Perl 5 you may have available.
perl v5.26.3                      2020-09-07                Mail::DKIM::DNS(3)