Omar Thameen <[EMAIL PROTECTED]> wrote:
> >
> > A few duplicate deliveries are harmless -- and as they're the fault of the
> > receiving system, if the recipient is annoyed, tell them to tell their
> > postmaster to fix their system, and not to be angry at you.
> Do you have any idea what types of issues or configurations cause this
> to happen?
Their mailserver is unstable or does not conform to RFC821/2821. Their
network is unstable. Who knows? For whatever reason, they are failing to
issue the required 2xx code after they see the end-of-data <CR LF "." CR LF>.
Without the 2xx response, the sender is required to consider the delivery a
temporary failure.
> I'd like to be able to point them in the right direction, and the biggest
> problem is the fact that it's not happening with any other mail they
> receive. Thus, the fingers get pointed at my system.
qmail tends to excercise other receiving MTAs somewhat differently than
sendmail, for instance -- perhaps their smtpd can handle fifty messages dumped
serially over a single SMTP session, but can't cope with qmail opening a
separate session for each message. In that case, their incoming smtp
concurrency is set too high, and that's a configuration problem on their end.
Charles
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Charles Cazabon <[EMAIL PROTECTED]>
GPL'ed software available at: http://www.qcc.sk.ca/~charlesc/software/
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