[ Thanks to Morten W.
Petersen for this link. ]
“One of the best features about Thunderbird is the spam (junk)
mail filter. Thunderbird has a built-in filter which can be
adjusted and tuned in for your own pleasure. You may need to spend
a week or two training it what’s spam and what’s not spam, but it
will be worth it. 🙂“The first you need to do is localize the settings panel for the
spam filter, if you go Tools > Junk Mail Control you should get
this window…”