A few months ago I changed the way my email server works. Instead of using POP3 to download the mail and then filtering it on the client side using procmail, I configured the system to filter the mail on the server side so that I could read mail using IMAP. At some point during that change I broke the Spam Assassin set-up so that Bayesian filtering no longer worked. The upshot of this was that I was suddenly getting an extra 150 or so pieces of spam that were ending up in my inbox rather than being shunted off to my spam folder. This was most obvious in the mornings when I’d always wake up to 70 or 80 unwanted messages in my inbox. Despite this being an annoyance, it never became enough of an annoyance for me to spend the few hours it would take to fix it.
Then this morning I found only ten or so spam messages in my inbox. My immediate response was to think that there was some kind of problem with my mail server (the recent trackback denial of service attacks have made me sensitive to problems like this and the constant stream of spam is a useful heartbeat to monitor).
But once I’d woken up a bit more I realised that that wasn’t the problem. Actually there wasn’t a problem at all. All that had happened was that yesterday I had finally got round to upgrading to version 3 of Spam Assassin (only 18 months after it was first released!) And this version is much better at catching spam than the old version. So I’m seeing less spam in my inbox again. Which is, of course, good.
Not sure if the Bayesian filtering has started working again tho’. Need to check that over the weekend.