The amount of spam just about doubled over prior years. Both 2005 and 2006 saw around 20,000; this year saw nearly 50,000. In summary over all years, the collected data has almost reached six figures.
In accordance with the doubling, the amount of non-spam falsely identified as spam also approximately doubled, from 83 to 156.
Thunderbird has become a significantly smaller contributing force to spam management, identifying only 152 correctly, as opposed to nearly 1,000 last year. Of course, SpamAssassin only let through a few hundred this year, compared to nearly 1,600 last year. Still, the ratio of work I do to the work Thunderbird does is 3:2, and last year it was closer to the reverse.
I manually marked 239 spam messages that went through all the defenses, substantially less than the 735 of the previous year.
At this point, there are more interesting things to do - until the other side evolves tactics to overcome SpamAssassin, it looks like my configuration, particularly the SA threshold, is doing as well as it can. Moreover, it's no longer an issue I think about much, aside from skimming through each day's spam to consider whether anything good got thrown out with the bad. It's mostly a matter of luck whether I spot something since the incidence rate is so apparently low. Get in touch if you feel like I'm ignoring your messages; I don't ignore messages if I get them.
I expect the day will come when I look in my mailbox and think, "well, that was clever," and hope an SA upgrade can rise to the challenge. Until then, there's that graph to entertain me every day while I do other things.