I have greylisting set up in Exim without the need for anything external.
It doesn't have any allowances for bypassing yet as that is trivial at
this point. It is the last thing I have configured in acl_smtp_rcpt before
the explicit accept. I understand the implementation only allows the
possibility for using one Memcached server. I wouldn't mind if anyone
would like to offer any constructive criticism and/or ways to clean up the
implementation. The configuration can be found here:
http://mail.yournetplus.com/d.hill/exim-greylist-memcached.conf
The two examples I used as a basis in getting it to work were taken from:
http://wiki.exim.org/GreylistMemcachedPerl
which shows a Perl implementation that uses the Perl module
Cache::Memcached, and:
https://secure.grepular.com/blog/index.php/2009/05/13/accessing-memcached-from-exim/
which shows the basics on how to use Memcached within Exim using the
${readsocket{}} string expansion.
-d
