Spam With Cut off Subjects

[Kaleb Hosie <kh...@spectraaluminum.com>]

I've noticed a lot of spam coming in recently with cut of subjects and the
message within an rtf, pdf or zip file.

I'm starting to believe that Bayes isn't able to catch these (however that
hasn't stopped me from trying to train it anyways)

Here are a few examples of subject lines we have got:
" friend"
"Rowded with dudes (reel l"
"full abilities of wh"

What recommendations would I be given to help catch these?