Chris Edwards wrote:
> | Hi all, I am getting the occasional reports from users about multiple
> | deliveries. We are exim 4.24.
> |
> | It only happens rarely and then only to off campus addresses. Is it
> | possible there is some timing issue, where exim sends the message and
> | does not get an ack in time so sends it again. I am afraid I don't know
> | what MTA is at the other end. If any of you have seen this before or
> | have any ideas I would be grateful.
>
> One possible cause of multiple deliveries is if the receiving server takes
> too long to return the final 2xx response after the sending client has
> sent the payload and terminating `.'. The sending MTA may time out and
> retransmit the message later - hence duplicates occur.
>
> See RFC 1047 for a discussion of this.
>
> However, I assume this is mail your site sends _out_ that's affected ? -
> in other words, there is no single slow receiving MTA that the finger
> could be pointed at ?
>
> Perhaps try to get hold of Received headers of some samples, and see if
> you can tie these up with logs.
>
> --
> Chris Edwards, Glasgow University Computing Service
>
> --
>
> ## List details at http://www.exim.org/mailman/listinfo/exim-users Exim details at http://www.exim.org/ ##
>
>
This sounds *very* client/connectivity-related.
Are the users perchance using IMAP on-campus and POP off campus?
Might they have POP with 'leave messages on server'..
Or (most likely) - are they successfully downloaidng the message, but
not (being able to) to properly complete that particular POP
transaction, w/r message is still flagged for DLD?
(not a bad thing, BTW, just confusing unil the problem can be corrected).
HTH,
Bill Hacker
>
