--On 2 November 2007 11:39:56 +0000 Graeme Fowler <graeme@???>
wrote:
> On Fri, 2007-11-02 at 04:24 -0700, ikearns wrote:
>> However any mail that does get through that is destined for a resolvable
>> email address will then be delivered to the back end server(s) via and
>> Exim box running manualroutes. Should this message be undeliverable
>> (through the mailbox not existing) then this is sent back to the sender.
>> I believe this is common practise and as describes, required as a NDR.
>
> OK, so you could therefore do:
>
> require verify = recipient/callout
> domains = +local_domains
It's already too late. His anti-spam platform has already accepted the
message for delivery.
>
> or a variant thereof, in an appropriate place in your ACLs - perhaps in
> the RCPT ACL, so it's done *before* spam and virus scans take place.
> This way Exim will call forward to the backend servers and validate the
> recipient address as part of the SMTP transaction, thus saving on AS/AV
> resources since the RCPT call will be rejected before DATA if the
> recipient mailbox is invalid.
>
> Your backend servers will then not generate any NDRs since invalid
> recipients will never get to them.
>
> This depends, of course, on your backend servers being able to reject at
> RCPT time rather than doing accept-and-bounce.
>
> Graeme
--
Ian Eiloart
IT Services, University of Sussex
x3148
