DOCUMENT:Q180547  20-NOV-1999  [exchange]
TITLE   :XADM: Messages Generate NDR When Sent to Certain Sites
PRODUCT :Microsoft Exchange
PROD/VER:winnt:4.0,5.0,5.5
OPER/SYS:
KEYWORDS:kbusage 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
========

Any message sent from the local Exchange Server site to another specific site is
immediately rejected with a non-delivery report (NDR). The Event Log typically
contains 254, 142, and 290 information and warning events similar to the
following:

   254 - MSExchangeMTA - X.400 Service - "Unable to correctly route the DN
         ... address using information in the gateway address routing
         table.
         The O/R address matches the local site address space

   142 - MSExchangeMTA - X.400 Service - "The MTA was unable to route the
         recipient DN ... the X.400 address ... the message MTSID... Check
         the routing table for a possible incorrect routing configuration.

   290 - MSExchangeMTA -  X.400 Service - "An NDR has been generated for
         MESSID, it was originally destined for DN ... and was to be
         redirected to ."

CAUSE
=====

One or more recipients in the local site have additional X.400 e-mail addresses
defined in their properties that duplicate the address space or spaces of the
destination site for the message.

RESOLUTION
==========

There are two ways to resolve this problem, depending on your configuration:

 - If the additional e-mail addresses causing the problem were added in error,
   you can remove them from whatever recipients have such addresses specified.
   If the problem occurs suddenly, it is likely that someone has recently
   created or modified a recipient in the site with an additional e-mail address
   that duplicates the address space of the other site to which you can no
   longer send messages. In this case, you can try listing the mailboxes in
   order of date modified to try to isolate the mailboxes that were changed.

 - If the addresses are X.400 addresses and the address space of the other site
   is truly shared with the local site (up to OU4), you can enable sharing of
   X.400 address spaces in the Exchange Administrator program (select the "Share
   address space with other X.400 systems" check box in the Site Addressing
   object). This option should be used with care, as it disables the sanity
   checks and makes it possible to create undetected loops if the organization
   routing is not configured correctly.

MORE INFORMATION
================

X.400 e-mail addresses for all recipients in a site are scanned each time
routing is recalculated, and a compilation of these is stored in a property of
the Site Addressing object. This property is consulted when the MTA routes
messages; if the destination address space of a message matches an address space
in this property, the MTA sends an NDR on the message because routing for the
message is ambiguous, unless the sharing of X.400 addresses spaces has been
enabled (it is not enabled by default).

This behavior is by design and represents normal sanity checking performed by the
MTA.


Additional query words: X400 address share routing calculation

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

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