David Dyer-Bennet [mailto:[EMAIL PROTECTED]] wrote:
> I just saw mention on bugtraq of spammers trying to exploit
>
> RCPT TO: <"[EMAIL PROTECTED]"@relay.host.name>
>
> (where "relay.host.name" is the reverse dns name for the system
> they're trying to relay through).
>
> I wasn't sure how qmail would handle this, so I did a couple of quick
> tests. Russel, hope you don't mind my bouncing one of them off one of
> your systems.
>
> What happened was that the mail was *accepted*, and then bounced
> (qmail seems to have ignored the quotes in the address). This is
> better than being an open relay by a lot, if not exactly perfect
> (perfect means rejecting the relay attempt before accepting the mail,
> of course). Of course in a real spam situation, the bounce would
> bounce and become the problem of the intended-relay sysadmin. And
> would it bounce once for every single name in the humongous list?
> Dunno, didn't try that. I've already given up and configured to drop
> doublebounces silently, anyway.
Can't anybody simply send mail to a bogus address on your machine and cause a
bounce? I don't see the problem here...
- David Harris
Principal Engineer, DRH Internet Services
