Definitely.
Question is, if you should forward a "sample" (header) of one
of the spam-mails...
We cannot, because the problem never gets that far. Our mailserver
rejects it like following: [1]
Jun 12 08:15:39 ns1 postfix/smtpd[8096]: reject: RCPT from mailout01.sul.t-online.com[194.25.134.80]: 450 : Sender address rejected: Domain not found; from= to=
So it never gets that far, it only causes a lot of work for our mailserver,
which is exactly the point of a DoS-attack. Lets say he had 100 machines
trying this. Then our mailserver would never do anything but reject
these connections - hence Denial of Service.
Unless we of course started blocking these IPs ...
[1] And no -- it is not a possibility to let them through.
--
Mads Martin Joergensen, http://mmj.dk
"Why make things difficult, when it is possible to make them cryptic and
totally illogic, with just a little bit more effort."
-- A. P. J.