Hi
Andrey,
we've implemented such a test in SpamChk, an external Test for Declude
Junkmail. There are two different test for less and more then 10 spaces. Some
spaces can occur sometime in real messages, but spammers try to hide a ID
at the end of the subject line so if there are (a lot) more then 10 following
spaces its a good test for spam.
In
any case you shouldn't take any action only for a single spam attribute like
this. In a weighting system as used in Declude Junkmail a space-test should
have a weight between 30 and 60% but not more to avoid false
positives.
Keep
in mind that with such a rule you can't catch more then 5% of
all spam messages having on the other side some false positives. As
part of a good balanced weighting system using over 50 DNS- RFC- and
content-based tests the effectiveness can be increased up to 90 -
95%.
Declude Junkmail costs something (not to much for it's functionality
and support)
SpamChk can be used with Junkmail and it's free.
Markus
Hey all. I am trying to create a primitive spam filter.
This one will specifically look at the subjects of messages.
Lots of spam mail has spaces in the subject followed by
some gibberish. So I have created a rule that would check the subject for 10
spaces in a row followed by something else.
It is working really well, except I suspect that it
trapped a few non-spam messages.
What kind of programs are out there that would produce
non-spam messages with lots of spaces in the subject
line?
