XCLN: Client Searches for Dcab32.dll on the Network

• Microsoft Outlook 97
• Microsoft Exchange Windows 95 client, version 4.0
• Microsoft Exchange Windows 95 client, version 5.0
• Microsoft Exchange Windows NT client, version 4.0
• Microsoft Exchange Windows NT client, version 5.0

SYMPTOMS

When you start a Microsoft Exchange client, you might observe that a search is made for a file called Dcab32.dll on the network. This observation would likely be made using a network sniffer.

CAUSE

When the Microsoft Exchange client loads the Address Book Provider DLL (Emsabp32.dll), the DLL searches for the presence of Dcab32.dll to enable Defense Messaging System (DMS) functionality. DMS is discussed in brief at http://www.microsoft.com/exchange/dms.htm. The search for Dcab32.dll will ultimately use the search path in the attempt to find the DLL. If the search path contains a network drive, this drive will also be searched. It is normal for the commercial release of Microsoft Exchange to do this search and fail to find the file.

WORKAROUND

For customers that do not want the Microsoft Exchange client to cause network activity while starting due to the Dcab32.dll search, it is recommended that network drives be removed from the search path. If network drives cannot be removed, a stub DLL can be obtained from Microsoft with the name Dcab32.dll that can be placed in the SYSTEM (on Win95) or SYSTEM32 (on NT) directory of the Microsoft Exchange client. The DLL provides NO DMS functionality, but it will be found by the Microsoft Exchange client search (thereby terminating the search), prior to use of the search path.

When the Microsoft Exchange client determines that the DLL does not contain DMS functionality, the client ignores it and continues loading.

STATUS

Contact Microsoft Technical Support for more information on the availability of this file.