Q198563: XFOR: Replies to Some Internet Mail Messages Fail

Article: Q198563
Product(s): Microsoft Exchange
Version(s): winnt:5.0,5.5
Operating System(s): 
Keyword(s): 
Last Modified: 16-JAN-1999

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The information in this article applies to:

- Microsoft Exchange Server, versions 5.0, 5.5 
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SYMPTOMS
========

When an Exchange Server recipient replies to some Internet messages, he or she
may receive a non-delivery report (NDR) indicating an invalid domain name. The
original in-bound message the recipient received from the Internet contains a
sender with an address similar to the following:

  <user@correct.domain.com>@incorrect.domain.com

In this example, "@incorrect.domain.com" is a non-existent domain name that has
been appended to the correct address, "user@correct.domain.com." The domain
"@correct.domain.com" is the valid domain name.

These additional domain name or names cause the message not be delivered. The
additional domain names may be added to the sender's address as a result of some
foreign mail configurations.

CAUSE
=====

In Internet Mail Service outbound mail, the domain name is found by looking for
the last @ sign in the address. In this case this is "@incorrect.domain.com."


The Internet Mail Service tries to resolve "incorrect.domain.com," which does not
exist, and fails. Thus, the message gets returned to the Exchange Server sender
as an NDR.

Now, on the way into the information store from the Internet Mail Service, the
address is checked to make sure it is usable. The check looks for the < and
> symbols, and clears out everything else except what is inside these
symbols. As a result, the message is cleaned up, and resent.

WORKAROUND
==========

The Exchange Server sender should resend the message from the NDR; it will
work.


Additional query words: reply double dual domains smtp mail fail duplicate

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Keywords          :  
Technology        : kbExchangeSearch kbExchange500 kbExchange550 kbZNotKeyword2
Version           : winnt:5.0,5.5
Issue type        : kbprb

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