Ignacio Garc?a:
> Hi there...
>
> I'm having a problem with one of our servers. We have been blocked by
> CBL because one of our customers have been sending many emails recently
> from his php-based bulletin system. This system does not send lots of
> emails (it's programmed to send 1 email each 10 seconds), but they have
> more than 3000 email accounts in their database, and maybe half of them
> are wrong, have typos, etc (unfortunately, the customer does not delete
> their wrong entries). Also, some unexprienced recipients of this
> bulletin may have also reported these emails as spam instead of
> UNSUBSCRIBING (I've seen this many times) from the bulletin. Anyway, my
> question is:
>
> What can we do to prevent this customer (and others in the future) to
> abuse our system this way? I was thinking of using postfix address
> verification, however there also also problems with this approach.
Use a sender-dependent source IP address to separate mail from
senders with good reputations from senders with poor reputations.
Specifically, use sender_dependent_transport_maps to select a
Postfix mail delivery transport name, and specify an SMTP transport
in master.cf with "smtp -o smtp_bind_address=x.x.x.x" to ensure
that their mail has the source IP address x.x.x.x.
Wietse
