Some emails bounce back on exchange server 5.5...Please help.

[Guest_imported]

We are running a Microsoft exchange 5.5 server for our mail. The person who set it up is no longer available. It had been running fine for the last few days. However, we have been having some problems lately. Some emails (very few) are bouncing back. I tried sending the same through hotmail and it works. However, the emails always bounce back if I try sending it through the company mail. The emails which bounce back are of two different domains. These never reach the recipients if I try sending them through our exchange server. But I can send the emails through hotmail. This is the message I get:

" Unable to deliver the message due to a communications failure The MTS-ID of the original message is: c=US;a= ;p=Bold Brain;l="DOMAIN NAME"-020423132829Z-1798"

Please note that I substitued my domain name with the words DOMAIN NAME in the message above.

What is the problem? Also, is there any web site or book that explains how to maintain the exchange server. The administrator when he was here used to perform maintenance every month. I need to do it till we find someone to take his place. I work for a very small company and any help your provide will be greatly appreciated.

Thanks, Ram.

 

[mlynch]

I do not have an answer but I have the same trouble . Certain mails to certain domains
do not resolve . I have ( I think ) checked all IMS settings and all appear correct . This
trouble is usually from the outside with your Internet Service Provider , but not always.
I will continue to investigate , and reply when appropriate .

M.L.

 

[chester27]

This looks like a DNS problem.

 

[tostfeld]

Do you have PTR records for your mail servers in DNS? If not, you will find many emails will fail (or just time out) because the receiving server can't do a reverse lookup on your mail servers.

 

[Adminman]

You server could be an open relay and the recipient's domain has your domain blocked. There are several good posts in this Forum which speak to the point of closing open relay servers.

Adminman