Google has finally enabled Gmail to fetch mail from other accounts. I use Gmail for a lot of my email, but if you send mail to some of my addresses, it still goes to my own server, and I download it with Thunderbird. Unfortunately, the accounts on that server get about 1000 spam messages a day. About 2/3 of them are filtered on the server by amavis. The rest make it into my inbox, where the Bayesian filter in Thunderbird tries to handle them. Sadly, it fails.
I’m going to configure Gmail to fetch my mail and see if it can do a better job. I get plenty of spam on my Gmail account as well. I have over 4000 spam messages in my Gmail spam folder, which throws away everything over 30 days old. However, Gmail seems to do a much better job than Thunderbird does, as I get less than five spam messages in my Gmail inbox every day.
Note: Actually this is what I’d like to do, but I can’t actually do it right now. I’m not sure why the Mail Fetcher options aren’t available for my Gmail account, but they aren’t, at least not yet. I’ll keep checking.