Re: [Exim] Desperation: Connection Reset by Peer

Martin W <veg@???> writes:
> It's fast - here is an extract of the bit where it fails:
> (leo is our mailhub - xxxxxx is the peer)

My first thought would be that something else in the data path (or
near it) could be resetting the connection.

Unfortunately your attached trace doesn't show what I'd look for next
to confirm that theory - examine the returned RST packets for signs of
different TTLs to the normal packets received from the remote mail
server ('tcpdump -v' is good for this.)

Recently I've encountered a firewall (Symantec's Velociraptor) that
will reset SMTP connections when it believes them to have breached the
protocol specification (which, it so happens, it wasn't.) I've also
seen connections reset by over-zealous network-nanny software (Websense,
Surfcontrol, etc)

All of these may well be at the remote site, rather than under your
control. Your best bet is probably to start a dialogue with their
admins (though that might be hard for the example you give -
BTinternet's mail is now also handled by Yahoo.)

James.