Error sending messages to one domain from SBS

[splufdaddy]

We are having trouble sending messages to a certain domain from our small business server. Recipients are not recieving our messages, and my users aren't recieving any notification that their messages weren't recieved.

When I track the message, I open up the message history and get an error:

"The object '*********00********' in the message tracking logs can't be found in the directory. The object may have been deleted. The tracking history may be incorrect."

The last two lines read:
SMTP: Started Outbound Transfer of Message
SMTP: Message Transferred to *****************00**********

Note that I didn't block anything out, that's what my log actually reads.

This happens for all messages sent to one domain. Does anyone have any ideas what this could be?

 

[58sniper]

Okay - that's interesting. Let's start with the basics.

Can you lookup the MX record for the receiving domain, using your internal DNS server?

Pat Richard, MCSE(2) MCSA:Messaging, CNA(2)

 

[splufdaddy]

Yup, just looked it up, and the lookup returned the same information that dnsstuff.com reports.

 

[58sniper]

Okay, assuming that you can ping that name, and the related IP address, do you have a reverse DNS entry for your IP address? (Do a lookup at dnsstuff.com)

Have you tried sending to the receiving domain from an account outside of your environment (GMail to the rescue)?

Pat Richard, MCSE(2) MCSA:Messaging, CNA(2)

 

[splufdaddy]

They're a major corporation, so it seems to just be us that can't get to them. However, our messages are being recieved by all of our other customers except this client.

Our small business server is only about a week old, so I'm guessing it's in relation to the move. I have 3 messages to aol.com accounts that have been in queue all morning too.

That lead me to look at our reverse DNS entry, which looks to be in order. Could our Reverse DNS entry be modified to be clearer and let our email through?

 

[splufdaddy]

Correction, looking at this report, it says that we don't have an A record. Should I contact my ISP about this?

 

[58sniper]

That'll certainly kill the AOL email, although the RFC says they can't deny it for not having a rDNS entry.

Pat Richard, MCSE(2) MCSA:Messaging, CNA(2)

 

[splufdaddy]

Another update, w/ some more information:

I turned on logging for the SMTP server, and in the logs I found this url:

http://postmaster.info.aol.com/errors/421rlynw.html

So it looks like AOL's problem is that someone else on this IP address has been sending spam to AOL. That explais AOL's problem, but not the problem from our client who can't recieve emails.