DOCUMENT:Q218188  08-MAY-2002  [exchange]
TITLE   :XADM: Sender Receives NDR When Sending to User From OAB
PRODUCT :Microsoft Exchange
PROD/VER:winnt:5.0
OPER/SYS:
KEYWORDS:kbExchange500preSP3fix

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The information in this article applies to:

 - Microsoft Exchange Server, version 5.0 
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SYMPTOMS
========

Microsoft Exchange Server versions 5.0 SP1 and SP2 may generate an Offline
Address Book (OAB) that results in an offline user occasionally receiving
non-delivery reports (NDRs) when attempting to send messages to particular
addresses in the OAB. The error message returned to the sender may be similar to
the following:

   No transport provider was available for delivery to this recipient.

CAUSE
=====

This may occur when two identical aliases exist for different users in separate
sites.


RESOLUTION
==========

A supported fix is now available from Microsoft, but it is only intended to
correct the problem described in this article and should be applied only to
systems experiencing this specific problem. This fix may receive additional
testing at a later time, to further ensure product quality. Therefore, if you
are not severely affected by this problem, Microsoft recommends that you wait
for the next Microsoft Exchange Server version 5.0 service pack that contains
this fix.

To resolve this problem immediately, contact Microsoft Product Support Services
to obtain the fix. For a complete list of Microsoft Product Support Services
phone numbers and information about support costs, please go to the following
address on the World Wide Web:

   http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS

NOTE: In special cases, charges that are normally incurred for support calls may
be canceled, if a Microsoft Support Professional determines that a specific
update will resolve your problem. Normal support costs will apply to additional
support questions and issues that do not qualify for the specific update in
question.

The English version of this fix should have the following file attributes or
later:

Component: Offline Address Book

+--------------------------+
| File name  | Version     | 
+--------------------------+
| Oabgen.dll | 5.0.1461.90 | 
+--------------------------+



STATUS
======

Microsoft has confirmed this to be a problem in Microsoft Exchange Server
version 5.0.

Additional query words:

======================================================================
Keywords          : kbExchange500preSP3fix 
Technology        : kbExchangeSearch kbExchange500 kbZNotKeyword2
Version           : winnt:5.0
Issue type        : kbbug
Solution Type     : kbfix

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