DOCUMENT:Q230498  29-JUL-1999  [exchange]
TITLE   :XCON: Message Looping NDR for Newly Created SMTP CR
PRODUCT :Microsoft Exchange
PROD/VER:winnt:4.0,5.0,5.5
OPER/SYS:
KEYWORDS:exc4 exc5 exc55

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The information in this article applies to:

 - Microsoft Exchange Server, versions 4.0, 5.0, 5.5 
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SYMPTOMS
========

You create a custom recipient (CR) for an SMTP address. After creating the
address, you send a test message to the custom recipient and receive a
non-delivery report (NDR) because of message looping.

CAUSE
=====

When the message is composed to the recipient, the default address is an SMTP
address, and is thus routed to an Internet Mail Service in the organization. The
server receiving the message, however, does not have that recipient in the
directory because of latency in the replication schedule, and attempts to route
on the Distinguished Name (DN) of the custom recipient. This results in the
message being passed back to the sending server, which generates a loop, and the
message transfer agent (MTA) generates an NDR with the loop detection message.

RESOLUTION
==========

To avoid the problem, allow time for directory replication to occur between the
two sites before sending mail to the newly created custom recipient. After
replication has occurred, the MTAs in the second site can resolve the custom
recipient back to the SMTP address and forward the message onto an Internet Mail
Service for final delivery.

Additional query words:

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Keywords          : exc4 exc5 exc55 
Technology        : kbExchangeSearch kbExchange500 kbExchange550 kbExchange400 kbZNotKeyword2
Version           : winnt:4.0,5.0,5.5
Issue type        : kbprb

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