I spent some time this afternoon trying to reduce the amount of spam that gets downloaded and dumped into my spam folder. Between SpamAssassin and Mail.app’s spam filters there’s basically no spam that makes it through to my inbox, but the sheer amount of spam being sent to symphonious.net, then downloaded from their to my home IMAP server before finally being processed by SpamAssassin is overwhelming and takes up a lot of bandwidth and processing time. Besides, with that much spam going into my spam folder I haven’t been bothered reviewing it so if there are any false positives they are pretty much doomed.

I’ve implemented two measures:

1. Any email with a spam score above 20 gets sent straight to /dev/null instead of going into the spam folder. That made a pretty huge difference to the amount of spam to review, but did nothing for the amount being downloaded.
2. Implemented a bunch of the postfix configuration options described at http://jimsun.linxnet.com/misc/postfix-anti-UCE.txt Hopefully that will block out the easily identified spam before it gets accepted at all and reduce the amount of email downloaded and SpamAssassin processing.

I also submitted the server to ORDB to check it for any open relay problems. Man, those guys are persistent – it’s tried connecting about 20 times so far from various addresses and trying to send to different places etc. I haven’t received its report back yet, but it seems to have been rejected with every attempt so it looks like I’ve got it all right.

Anyway, if you have any problems emailing me, leave a comment and I’ll look into it.