Hi there, I’m at the moment in the concept stage for the implementation of custom policies which will be attached to several postfix instances.
A brief description of what i have now: I have three postgres tables: mail_filter, mail_filter_rule and mail_filter_action a filter (mail_filter entry) can have one or many rules (mail_filter_rule entries) as well as actions (mail_filter_action entries) For example, Filter 1, could be something like, mail from: f...@bar.org and rcpt to: b...@foo.org and in this time frame 14:00-19:00 could be (and now come the actions in to play), "blocked" Filter 2, could be something like, mail from: domainX.com and rcpt to: b...@foo.org and in this time frame 10:00-13:00 could be "remove attachments of mime type Y and notify someone" I developed a small policy server [1] in rust, and at the moment the concept is working fine for actions like accepting, rejecting or even bcc at the SMTP protocol stage (i am using in at smtpd_recipient_restrictions). Normal, is how [1] works, you have to return only one action. But there are some other rules which must be checked in another stage, i would say with a after-queue content filter [2]. Rules are very flexible, but maybe most of them will have only one action reject or accept, that's why, i find better to do it at the SMTP protocol stage. Then, only If a rule contains some content filtering related action, i could return a "FILTER" action as stated here[3] and then a custom content filter will finish the job. I hope i am on the right way, if someone have some other thoughts i would be glad to read them. :) Best regards, Manuel Mely 1- http://www.postfix.org/SMTPD_POLICY_README.html 2- http://www.postfix.org/FILTER_README.html 3- http://www.postfix.org/access.5.html
