XADM: "Send As" Functionality Does Not Work When DPA Is Used as Authentication Method

ID: Q221434

The information in this article applies to:

Microsoft Exchange Server, versions 5.5, 5.5 SP1, 5.5 SP2

SYMPTOMS

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

Steps to Reproduce the Problem

Assign "SendAs" Permission for User1 to User2.

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

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 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
Version : winnt:5.5,5.5 SP1,5.5 SP2
Platform : winnt
Issue type : kbbug