Having trouble getting spamassassin working properly on my Linux server (SOLVED)

[mikeymikec]

I think this is one of those times where my lack of Linux troubleshooting skills shows. I'm in the process of getting my server ready to replace its aging predecessor (running Windows). POP/IMAP is working (dovecot), SMTP is working (postfix), but despite following these instructions:

Ubuntu-Mail-Server-Spam-Filtering-Guide/Postfix_Dovecot.md at main · ozfive/Ubuntu-Mail-Server-Spam-Filtering-Guide

This repository provides step-by-step instructions to set up automated spam filters using SpamAssassin for various mail servers on Ubuntu systems. The covered mail servers include Postfix, Dovecot,...

github.com

The instructions that I didn't follow in that guide was what's written in step 6 because I'm honestly not interested in having suspect mail routed to a different folder, I'm happy with just [SPAM] in the subject line and let the end user filter it as they please.

I'm in a situation whereby spamassassin (spamd) appears to be running, but I'm not seeing any sign at all that it's doing its job. For example, in test mails I'm sending around there are no SA headers, nor are there any signs of SA life in /var/log/syslog or mail.log (the latter seems to be where the Internet is generally in agreement that SA should be showing up in at the very least).

Server is running Ubuntu Server 24.x LTS with the latest updates, I've restarted spamd and postfix a couple of times apiece, but without any symptoms I'm seeing that I can work on, I'm a bit stuck.

 

[mikeymikec]

Yay, I solved it!

The instructions I followed weren't completely correct for a few reasons:

1 - Ubuntu Server 24.x doesn't create a spamassassin service, but spamd instead
2 - the instructions for editing master.cf were wrong (I found correct instructions in another guide):

https://www.transip.eu/knowledgebase/postfix-antispam-with-spamassassin/

This line was missing from the first guide:

smtp      inet  n       -       n       -       -       smtpd -o content_filter=spamassassin

3 - the master.cf instructions were likely wrong (for Ubuntu 24?) for another reason, they say:

spamassassin unix -     n       n       -       -       pipe
  user=spamd argv=/usr/bin/spamc -f -e
  /usr/sbin/sendmail -oi -f ${sender} ${recipient}

But the user should be debian-spamd.


One thing I learned along the way though:

dpkg -L spamd

Lists all the files installed by a package. Handy in the event that you want to find out where a configuration file is.