I wasn’t willing to scrap the SpamBayes engine though, so after getting my Thunderbird setup working again, I dug into the instructions on how to install the 1.04 version manually (the 1.1 alpha version is the one that the SSL update broke). It wasn’t all that difficult, but I don’t recommend it for anyone who isn’t at least a power-user… I had to install an older version of Python to get it working properly (it only partially works with the 2.6 version that Ubuntu comes with), and chain it through
stunnel to get SSL support (that’s why I wanted the 1.1 alpha in the first place, it supports SSL without
stunnel). And without ThunderBayes, you have to go through a web interface to train it, which is a pain in the tail. But eventually I got it all working properly.