DB won't train, 'Unsure' about everything

[Adrian]

Thinking about this, you may prevent these reserved tokens creating an
entry if they happen to turn up in a mail.

But as I've mentioned, these go back many years, to days when maybe you
didn't have them as reserved words, and running on an Sqlite DB
until recently.

There are over half a million tokens.  I imagine these turned up by
coincidence,  But, bearing in mind they were all in spams, maybe
someone has found a way to break bogofilter maliciously.