[spambayes-dev] Slightly new tactic

[T. Alexander Popiel]

I just noticed a new variation on an old spammer tactic
in my unsure folder: in HTML mail, text colors which
almost but not quite match the background color.  I know
that matching the background exactly is an old tactic,
but this spam seemed to have a random adjustment to the
font color, by plus or minus 3 quanta on the blue scale.

The mail still showed up as high unsure, and I don't
think we bother with trying to determine which text in
a multipart or HTML message is actually visible; however,
if we ever do try to figure that out, then we may want
to put some wiggle room on the color-matching.

- Alex