Despite my regularly tagging emails as junk or "not junk" many recent iterations of Thunderbird fail to identify correctly the continual spam that contains mixed upper and lower case letters within words, absolute gibberish that isn't recognizable as English, and patterns of email that I would think developers of Thunderbird could improve recognition for, as clearly being spam (i.e. online pharmacies who continually hawk their (perhaps) counterfeit blue and yellow pills, and quote pharmaceutical brands.

Thunderbird, you need to go to remedial class and catch up on your learning!