I help an ISP with their mail setup and we are having a strange problem:
Spam is beeing forged from users at our system, who no longer exist to AOL
addresses who do not exist.
The message comes from xyzzy@??? (non-existant user) to
invaliduser@???.
AOL correctly bounces the message that comes back to us.
The problem is that our machine accepts the mail and then aparently bounces
the message back to aol.
What we want to do is reject messages to unknown users on our machine either
at smtp time, or if this is not possible, we want to drop messages from
<> to an invalid user into the bit bucket.
We could blackhole the unknown users, but that means we have to accept the message
and pay for the incoming bandwidth at 20 cents a meg.
Is there another way or better solution?
I'm sure there are tools to do this but am not sure which bits of the spec
deal with rejecting mail to unknown users on our machine. Spec references
or advice would be greatly apreciated.
I'd happily RTFM given a couple of section numbers to start with.
Regards, Kerry.
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Kerry Hoath:
kerry@??? or khoath@???
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