Spammer spoofing

[Tom Anderson]

----- Original Message ----- 
From: "Peter Bishop" <pgb at adelard.com>
> # pretend user does not exist if looks like "probe"
> :0H
> * !^Subject:
> { EXITCODE=67 HOST }

Sounds like a good idea, but only checking for no subject is dangerous. 
Lots of people send email forgetting to include a subject, especially if 
it's a quick note done in haste.  Is there more detail which can be checked 
to determine if this truly is a probe?  Maybe combine the no subject with 
the spamicity to determine if you're going to reject it.

Tom