Cannot send email to hotmail.com !?!?

[J]

Hi,

I am running Exchange 2003 on Windows 2003. I have several SMTP queues that
are stuck on retry and are unable to get the mail delivered. The domains
include hotmail.com and bt.com (as well as a few others). Having turned on
SMTP logging I am getting application event log warnings 4006 which either
tells me that delivery to the host 'ip_address' failed due to a semiphore
timeout period expiring or because the remote host dropped the connection.

We have had DNS issues and originally I thought this problem was definately
caused by reverse DNS lookup pointing to our old mail server and not the new
mail server, but the reverse DNS entries are now fine (last 2 days) and still
I am experiencing this problem.

I can telnet into the remote mail servers and send an email through that
way, but mail in the queues just will not go.

Please help. I appreciate any questions, suggestions or comments.

Thanks

J

[FD]

Are you using a PIX firewall?
Look at Q320027 at Microsoft Technet

"J" <J...@discussions.microsoft.com> wrote in message
news:93A4C29C-D25D-4ED3...@microsoft.com...

[J]

No, we are behind a linux NAT firewall that is all.

I seem to have managed to resolve the problem now. Although only a little
time will tell. I added into the DNS, forwarder addresses for external DNS
servers (as provided by my ISP). I can't be certain that was the solution as
I still have a niggling thought that it could have been due to DNS still
updating. Although the problem did go away all of a sudden which wouls
suggest it is more likely to be the DNS forwarding that was an issue.

Thanks.

If the problem comes back or I identify the solution more distinctly then
I'll post here again.

J

[J]

I now think I have better identified the problem. It seems to have been
related to Anti-Virus software on the server. Due to unforseen circumstances
the build had been slightly rushed and standard Norton Corporate Edition had
been installed to protect the server itself. By default this has enabled an
Internet E-Mail Auto Protect feature which it seems may have been altering
outgoing details of the SMTP communication and thus messing up reverse DNS
lookups.

Having disabled that option, emails go out fine to all domains.