You probably want to set the option below. This will cause your mail
server to not accept mails that are addressed to recipients that dont
exist, and they will be stuck on the sender's system instead of yours.
Since that will usually be the system the spammer is using to spam,
that is a good thing..
receiver_verify Type: boolean Default: false
When this option is set, the addresses of recipients received from a
remote host are verified as they are received, provided the sending host
matches "receiver_verify_hosts", the incoming address matches
"receiver_verify_addresses", and the sender address matches
"receiver_verify_senders", if either of the last two are set. If an
address is invalid, an incoming SMTP call gets an error response to the
RCPT command. If an address cannot immediately be verified, a temporary
error code is given. The "receiver_try_verify" option is less severe: it
operates in the same way, except that an address is accepted if it
cannot immediately be verified. Verification failures are logged.
On Fri, 16 Nov 2001, jens-ingo brodesser wrote:
> hello,
>
> is there a way in exim 3.32 to have sender verification and
> especially sender_verify_callback coming before a rejection because
> the user is a unknown user on the system.
>
> we have a lot of spam entering our queue like this : a lot of spam
> with forged sender addresses is sent to non existant users of our
> system (speculating on the existance of a default, catch all
> instruction), these mails get bounced and exim sends immediately an
> error 500 back, which the destination hosts reply with a 500 getting
> stuck in our queue then.
>
> what solutions are there to this dilemma?
>
> --
> jens-ingo
>
> --
>
> ## List details at http://www.exim.org/mailman/listinfo/exim-users Exim details at http://www.exim.org/ ##
>
>
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