Hi everybody,
(my english may be poor, please have mercy)
I am using Virtualmin GPL on Debian 7 and I try to optimize my spam filtering methods.
At the moment, I am filtering incoming mails with some RBL (especially spamhaus) to block spams. I did this by editing the “smtpd_recipient_restrictions” parameter in /etc/postfix/main.cf.
I am also using spamassassin to tag the remaining spams (the usual *** Probably Spam *** in the title). I did this with Webmin’s SpamAssassin module (SpamAssassin Mail Filter > Message Modification)
Untill now, this was OK to block enough spams. Unfortunately, it is no longer the case :’(
Thus, I would like to use spamassassin to block spams, preferably BEFORE they are accepted by the server, at SMTP transaction level. I tried to use the “header check” function of Postfix to block mails that reached a high spam level. Like this :
# cat /etc/postfix/header_checks
/X-Spam-Level: *{8,}/ REJECT Email rejected. Looks like spam.
But it is not working : the messages ares tagged by spamassassin (a lot of information added in the headers) but they nevertheless are accepted by the server.
I noticed that it is possible to delete mails if they are tagged as spam (Virtualmin > domain.com > Server Configuration > Spam and Virus Delivery) but I do not really like that idea of “deleting without warning”, whenever a mail is accepted by the server, i feel like I have to deliver it somewhere. That is why I would like to block mails during the SMTP transaction. Is it possible ?