Hello, As a fruit of my battle with spammers, virus et al. I also implemented the greylist policy server in an rpm package form. The core, is a simple perl script wich is included in the postfix package docs and examples. The trick of greylist is first time a client tries to send an e-mail it is responded as 'Service Unavailable' if it were accepted, so actually is not distributed nor accepted. Next time the same client tries to send the same mail, greylist response is 'DUNNO' so the mail follows its normal process, and it can suffer other resrictions. The positive site is that most of spammers and virus will not try to send the mail a second time, where all the usual MTA will try to send again the same mail after few minutes. The astonish result is we kill the most part of undesired mail. The negative part is we introduce a small delay in mail delivery. To implement this policy into postfix 2.1.x, you need to install the package postfix-policyd-greylist you can get for SuSE 8.2, 9.0 and 9.2 here: ftp://ftp.gwdg.de/pub/linux/misc/suser-gbv/rpms And then add the line from /etc/postfix/master.cf: policy-greylist unix - n n - - spawn user=nobody argv=/usr/bin/perl /usr/lib/postfix/smtpd-policy-greylist.pl in file '/etc/postfix/master.cf' and you also have to add the 'check_policy_service unix:private/policy-greylist' restriction in file '/etc/postfix/main.cf'. Tipically you should add it to 'smtpd_recipient_restrictions' list as is in the following lines smtpd_recipient_restrictions = ... reject_unknown_sender_domain reject_unauth_destination check_policy_service unix:private/policy-greylist ... NOTE: specify check_policy_service AFTER reject_unauth_destination or else your system can become an open relay. Once you've modified the files, you can load the new configuration with rcpostfix reload if you already had your postfix running. This greylist policy can run with SPF policy you can find in the same directory. Today I've also released a new SPF package release with some more docs. Hope this help you in the battle against undesired mail. Guillermo. -- Guillermo Ballester Valor gbv@oxixares.com Ogijares, Granada SPAIN Linux user #117181. See http://counter.li.org/ Public GPG KEY http://www.oxixares.com/~gbv/pubgpg.html