using sendmail as an smtp relay
ranz at devdata.net
Fri Jun 17 08:42:31 MDT 2005
I was wondering how you get proper send failures back to the originator when you use mail gateways. To qualify, we have sendmail setup which our mx's point to to receive email. sendmail then forwards the emails to the appropriate mail server for delivery. If that mail server issues a failure on receipt - like 550 - it tells sendmail - but then we need sendmail to issue that failure back to the originator - how is this possible when it is a broken session (so to speak)?
--> May need to setup LDAP user database for each domain so that gateway can properly fail incorrectly addressed messages.
--> How will it handle SPAM going through even with the above setup (LDAP/User List)?
--> It's not the same SMTP session from the originating mail server - so therefor the failure will get an "Email"
--> An option may be to leave the originating SMTP session open while delivery is performed to the internal mail server - but we are useing MailScanner and may be a delay - so this may not be possible - (How long is too long for an SMTP session (world standard) to time-out?).
Example - mail server sends a "over quota" error - which it will send to sendmail - but the originator doesn't receive this.
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