Tuesday, November 29, 2005

Some relatives, for whom I provide email aliases fromone of my domains, have been complaining about increasing amounts of spam. Well, don't we all. Unfortunately the relatives in question live in a sort of telecommunicational black hole which apparently has at least some telephone wires made from aluminium and which date from the immediate post-war period (Second World War, that is). DSL won't be available until the whole village is rewired, and even dialup can't max out a 56k modem. Understandably even a few spams make email access a torture.

So, what better opportunity to upgrade the server's SpamAssassin installation from 2.something to the recently (September) released 3.1. The basic upgrade is simply perl -MCPAN 'install Mail::SpamAssassin'. Additionally I installed Mail::SPF::Query ; it's not required, but its absence produces a steady stream of log warnings, and it should be useful for classifying mail from servers with correctly implemented Sender Policy Frameworks.

Many configuration directives have changed, so /etc/mail/spamassassin/local.cf needed updating. In particular, rewrite_subject 1 needs to be changed to rewrite_header Subject *****SPAM***** to ensure spam is visibly marked as such.

This page: http://brneurosci.org/linuxsetup49.html contains a useful summary of issues encountered with typical SpamAssassin installations and upgrades.

As could be predicted, having completed the upgrade, the spammers seem to be taking a break from their nefarious activities, so it'll be a day or to before I can be certain it's not producing too many false positives, and implement some spam-deleting procmail rules...

Posted at 8:49 AM |Comments (0)