DOCUMENT:Q221434  07-NOV-1999  [exchange]
TITLE   :XADM: "Send As" Functionality Does Not Work When DPA Is Used
PRODUCT :Microsoft Exchange
PROD/VER:winnt:5.5,5.5 SP1,5.5 SP2
OPER/SYS:
KEYWORDS:exc55 exc55sp1 exc55sp2 EXC55SP3Fix

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The information in this article applies to:

 - Microsoft Exchange Server, versions 5.5, 5.5 SP1, 5.5 SP2 
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SYMPTOMS
========

When you use Distributed Password Authentication (DPA) as the authentication
method, "SendAs" functionality does not work correctly.

Steps to Reproduce the Problem
------------------------------

1. Assign "SendAs" Permission for User1 to User2.

2. Log on as User2 and make sure you are able to send as User1.

3. Log on as User3 and send message using User1 in the From field. This message
   will also get delivered.

This problem does not occur when Windows NT LAN Manager (NTLM) is used as the
authentication method.

CAUSE
=====

This behavior is caused by a logic error in the code. The main difference
between Windows NT and Membership security is that with Membership, one Windows
NT account, the "broker," is mapped to all the Exchange Server mailboxes.


RESOLUTION
==========

To resolve this problem, obtain the latest service pack for Exchange Server
version 5.5. For additional information, please see the following article in the
Microsoft Knowledge Base:

   Q191014 XGEN: How to Obtain the latest Exchange Server 5.5 Service Pack

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

Component: Information Store

+-------------------------+
| File name  | Version    | 
+-------------------------+
| Gapi32.dll | 5.5.2561.0 | 
+-------------------------+
| Mdbmsg.dll | 5.5.2561.0 | 
+-------------------------+
| Store.exe  | 5.5.2561.0 | 
+-------------------------+


STATUS
======

Microsoft has confirmed this to be a problem in the Microsoft products that are
listed at the beginning of this article. This problem was first corrected in
Exchange Server 5.5 Service Pack 3.

Additional query words: SendAs DPA NTLM Authentication

======================================================================
Keywords          : exc55 exc55sp1 exc55sp2 EXC55SP3Fix 
Technology        : kbExchangeSearch kbExchange550 kbZNotKeyword2 kbExchange550SP1 kbExchange550SP2
Version           : winnt:5.5,5.5 SP1,5.5 SP2
Issue type        : kbbug
Solution Type     : kbfix

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Copyright Microsoft Corporation 1999.