[exim] smtp lost connection (again without removing details)

mail server taking too much time to connect

_____

For some reason, one of the servers can't connect to my mail server.
Whenever a user tries to send email from that server to my server, the
message won't go through and I see the following in the logs
(var/log/exim/mainlog):

2007-02-15 08:55:52 SMTP connection from (uwo.ca) [129.100.74.146] lost
while reading message data (header)


this problem occurs only with this uwo.ca mail server (as far as I know).

In fact, trying dnsreport.com tool on any of my server domains, I am getting
the error message

" ERROR: I could not complete a connection to any of your mailservers!

ateer.com: Timed out [Last data sent: RCPT TO: ]

If this is a timeout problem, note that the DNS report only waits about 40
seconds for responses, so your mail *may* work fine in this case but you
will need to use testing tools specifically designed for such situations to
be certain.
"


Can someone help/advise?

Thanks.