Steven Jones wrote:
> At present our servers bounce with "no valid user" is this the best tactic?
Depends on what you mean by "bounce".
> or is it simply better to stop such bounce msgs? while polite, spammers are
> taking the p*ss....
If you mean your server gives a 5xx at SMTP time, that's fine. If it is
accepting the message at SMTP time (2xx) and then generating a bounce it
attempts to deliver, that's bad.
Let the remote side generate and attempt to deliver the bounce. There are
three malicious cases for the remote side and here's why you want to just
reject at SMTP and let them handle the bounce.
a: It's a virus. Chances are the virus isn't going to generate a bounce when
you 5xx it. So no bounce is generated.
b: It's a spammer or a spammer via proxy. Again, chances are they aren't
going to generate a bounce when you 5xx it.
c: It's an open relay. In which case their system generating a few dozen
thousand undeliverable bounces in a short amount of time should clue them in
that they have a problem they need to fix ASAP. If not the few bounces which
hit legit people should generate some nice nastygrams to postmaster which
should clue them in. Either way the bounces they generate is a symptom of
their problem and of little concern of yours.
--
Steve C. Lamb | I'm your priest, I'm your shrink, I'm your
PGP Key: 8B6E99C5 | main connection to the switchboard of souls.
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