Markus Stumpf writes:
> 1) There are mailservers that don't accept more than n concurrent
> connections from the same IP (while they still have the capability for
> open slots for other IPs).
> However this causes them to first "see" the connection and then
> dropping them. I wouldn't call that "poor [conf/admin/mta]".
Right, that's fine.
> 2) If a system is only accepting n connections a time, I have
> concurrencyremote set to 4*n and I just received a bulk with 3*n
> messages to that host, I will probably get n-m messages through and
> 2*n messages get blocked by either tcpto and/or the messages become
> marked as "unreachable" and go to the backoff list.
Okay, then what you're asking for is for qmail to special-case those
hosts which concurrently have TCP connections open and are not serving
new connections (either refusing connections or closing them
immediately, or giving a 4xx response to the smtp greeting). The
treatment that you want is to immediately retry mail when one of the
existing connections closes.
Or to put it a different way, you want qmail to recognize and remember
those hosts and when one of that host's connections closes, adjust the
retry schedule for the next message bound for that host. However, the
next message very likely will be retried in five minutes. So why go
to all the bother of recognizing and remembering those hosts just to
gain five minutes?
Of course, neither of us are solving the same problem as the original
poster posed. We're presuming that the destination host is
well-administered, and quickly rejects connections it cannot
immediately handle.
--
-russ nelson <[EMAIL PROTECTED]> http://russnelson.com
Crynwr sells support for free software | PGPok | Government schools are so
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