deleting mail with spamassassin

msound · 10-24-2005, 11:26 AM

I have a postfix mail server running spam assassin and I'd like spam assassin to automatically delete messages marked as spam. I know this can be done but I don't know if I can do it with spamassassin or if I need to do it with a header check script in postfix.

I already know the risk of deleting messages marked spam. We've been testing it for 4 weeks and havent had any false positives. I know users can setup a mail filter in their email client but we have some users on dial up who get 200 emails a day and theyre tired of waiting for all of the crap to download.

If anyone could tell me how to configure spamassassin or postfix to do this I'd appreciate it.

hawarden · 10-27-2005, 01:00 AM

We run sendmail, spamassassin, and procmail on our mail server. Spamassassin only tags the email as spam or not. We have the handling of the tagged email done for each user in the .procmailrc file in each home directory. That way each user can decide how they want their spam handled. I'm afraid I don't know about postfix configuration. If I remember correctly, in our setup the user's .forward pipes the mail into procmail. From what I vaguely remember from when I set it up a couple years ago, your postfix fills the same slot as our sendmail, and I think I recall documentation giving instructions for configuring procmail/spamassassin with postfix.

I found this link, hope it helps.
http://traxel.com/doc/spamassassin-setup.html

msound · 11-03-2005, 10:51 AM

Thanks for the reply Hawarden.

Fortunately I was able to figure out a really easy way to the spam using Postfix. I use the Postfix header_checks feature to filter out messages that have been marked as spam by spam assassin. Those messages are redirected to a spam mailbox but I can configure Postfix to discard those messages if I want.

Here's how to configure Postfix to automatically filter messages marked as spam, so the messages never hit the users' mailboxes:

Postfix main.cf file

Code:

header_checks = regexp:/etc/postfix/header_checks

Spam Assassin local.cf file

Code:

required_hits 8
report_safe 0
rewrite_header Subject SETSPAM
bayes_autolearn 1
bayes_auto_learn_threshold_nonspam 1
bayes_auto_learn_threshold_spam 5
whitelist_form	*@mydomain.com

Postfix header_checks file

Code:

header_checks
/^Subject: SETSPAM/		REDIRECT spam@mydomain.com

Restart Postfix and you're all set. If I wanted to simply discard all messages marked as spam, I could change my header_checks file to:

Code:

header_checks
/^Subject: SETSPAM/		DISCARD

Pretty cool huh?

Klaipedaville · 09-11-2014, 12:25 AM

****Please, disregard information below. It is incorrect.****

I understand this post is very old but I would like to comment on it.

That's a great example actually with its tiny little trick! It took me quite some time to figure it out where the point was.

The matter is that when you change your subject in spamassassin like this:

Code:

 rewrite_header Subject *****SPAM*****

regexp treats ***** as one word (character) SPAM as the second word (character) and ***** again as the third word (character). Therefore you can use it to your advantage. The last commenter changed it to one word of his own at all like this:

Code:

/^Subject: SETSPAM/

and it worked OK. Now if you keep the original that is *****SPAM***** and create your rule like this

Code:

 /^Subject: *****/

it will also do a perfect job and work as good.

Klaipedaville · 09-13-2014, 05:15 AM

Please, disregard my last post. Sorry. It is not right at all. It will block every incoming / outgoing email.

This one is all wrong:

Code:

/^Subject: *****/

The correct regexps to block SPAM are:

Code:

/^Subject: .*\*\*\*\*\*SPAM\*\*\*\*\*/

or

Code:

/^Subject:.*\*{5}SPAM\*{5}/

The number of asterisks in front of and after the word SPAM should match the number you put in your rewrite_header Subject *****SPAM*****.
It has 5 asterisks in my case therefore I put 5 or \*\*\*\*\*
The first .* matches any number of any special characters, it makes the rule harder and helps it match / catch more spam.