XFOR: 5.0 and 5.5 Internet Mail Services Do Not Do AUTH NTLM Between Each Other

ID: Q195201

The information in this article applies to:

Microsoft Exchange Server, version 5.5

SYMPTOMS

The Internet Mail Service cannot support an authenticated SMTP connection between an Exchange Server 5.0 computer and an Exchange Server 5.5 computer. When the Exchange Server 5.0 computer tries to create a secure SMTP connection to the Exchange Server 5.5 computer, it will fail with a 502 authentication error, and users will get the following non-delivery report (NDR):


   One or more mandatory argument(s) were missing from the recipient
   MSEXCH:IMS:POF:FDRC:NTS2 3502 (000B0981) 502 Server does not support
   AUTH.

When the Exchange Server 5.5 computer tries to create a secure SMTP connection to the Exchange Server 5.0 computer, the version 5.0 server computer returns a 500 command not recognized response.

CAUSE

Exchange Server 5.0 uses the SMTP extension XAUTH to set up NTLM authentication. Exchange Server 5.5 uses the SMTP extension AUTH to do this. When going from version 5.0 to 5.5, the server computer running Exchange Server 5.0 quits the SMTP session when it does not see XAUTH in the list of extensions offered by the computer running Exchange Server 5.5. When going from version 5.5 to 5.0, the server computer running Exchange Server 5.5 sends an AUTH NTLM command to the server computer running Exchange Server 5.0, which returns a 500 command not recognized response.

RESOLUTION

To resolve this problem, obtain the latest service pack for Exchange Server version 5.5. For more 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: Internet Mail Service


   File Name      Version
   -------------------------
   Msexcimc.exe   5.5.2394.0

STATUS

Microsoft has confirmed this to be a problem in Microsoft Exchange Server version 5.5.

MORE INFORMATION

To resolve this issue, the fix only needs to be applied to the server computer running Exchange Server version 5.5, no changes are required on the server computer running Exchange Server version 5.0.

To install the hotfix, please perform the following step:

Copy the Msexcimc.exe file included in the hotfix to the following location:

Exchsrvr\Connect\Msexcimc\Bin

Keywords : exc55sp2fix
Version : WinNT:5.5
Platform : winnt
Issue type : kbbug