Disabling the GMail spam filter and handling it yourself using SpamAssassin

I've been using GMail ever since they decided to allow users to download their mail using POP. I was happy reading my email as usual in mutt. The only problem was that I had to log onto the website once in a while to clear out my spam folder and fish out the false positives.

However, as the amount of spam I receive daily started growing exponentially (in part thanks to my involvement in Debian), I became more and more dissatisfied with this solution. I had to login several times a day just to keep the levels of spam down to a manageable level. I tried emailing the GMail support team a few times without success.

The solution came just as I was looking at switching to a different email provider: IMAP access.

Using fetchmail, I can now download my received and sent mail using POP and then download (and purge) the contents of my spam folder. Here are the relevant lines of my ~/.fetchmailrc:

poll pop.gmail.com protocol pop3 user "fmarier@gmail.com" is "francois" password "" fetchall ssl
poll imap.gmail.com protocol imap user "fmarier@gmail.com" is "francois" password "" folder "[Gmail]/Spam" fetchall ssl

I can then run all of my mail through my own SpamAssassin filter (to which I added these excellent custom rules) and sort my mail in one of three folders:

• definitely spam (conveniently located in /dev/null) for a score greater than 12
• probably spam (I need to check those manually once in a while)
• not spam for messages with a score less than 5

This is done using procmail with the following bit in my ~/.procmailrc:

# Use spamassassin to check for spam
# (only check messages < 400kB so that it doesn't choke) :0fw:/etc/mail/spamc.lock
* < 409600
| /usr/bin/spamc

# Throw away messages with a score of > 12.0
:0:
* ^X-Spam-Level: \*\*\*\*\*\*\*\*\*\*\*\*
/dev/null

:0:
* ^X-Spam-Status: Yes
/home/francois/mail/spam