Messages not being delivered to specific domain

[drace1111]

Welcome to Exchange hell.

I have some emails in queue to a certain domain that just will not be delivered. I've tried all the usual fixes to no avail. Here's what I've done so far:

I have successfully sent emails from Yahoo and MSN, so soemthing is broken between our server and theirs.

Telnet to port 25 on remote SMTP server - I successfully sent a message to the recipient this way. No problems were encountered.

Tried using NSLOOKUP to verify correct DNS resolution - Resolves to the correct IP address. DNS seems to be working.

Went to DNSREPORT.COM to check our domain as well as the remotes - Our domain has a reverse DNS entry, but their domain does not. This might be a problem if we were checking reverse DNS, but we aren't. Besides, we are sending to them.

Called the admin of the other domain - He tells me that they aren't blocking anything (that he knows of).

Something on our Exchange server must be screwy, but I can't find it.

Any thoughts?

 

[BigFunkyChief]

I have the same issue with 1 domain.

Have you tried running the SMTPDiag tool to troubleshoot? In my case, 1 out of every 10 connections would go through using SMTPDiag, so eventually forcing the connection got the message through.

Also, we have 2 Internet connections...and over our satelitte connection, we have no trouble sending to this domain at all...so my guess is my issue somehow lies with my ISP.

 

[drace1111]

I just ran SMTPDiag, and everything appears to be working correctly. The only problem was an SOA serial number mismatch, which shouldn't really affect anything. DNS resolves correctly, sender nd recipient are okay, and the connection to the remote server is successful, yet messages to this domain sit in queue.

WTF?????

 

[gurner]

Strange, i'd follow the reverse DNS issue out of curiosity, but you say you are making direct delivery?

You have no connectors forwarding to an ISP at all?

who does your DNS lookups after your internal DNS servers?

i'm not in front of an Exchange box at the mo, but i may have a dig around tomorrow


Gurner

http://www.divineparadox.co.uk