MSMAIL32 Error Occurs When Data is Cached Across Bad Link

• Microsoft Windows NT Server versions 3.5 and 3.51

SYMPTOMS

When you send a mail message using MSMAIL32.EXE in Windows NT, the following error message appears:

   [023] Message was not delivered: message file was corrupted.

CAUSE

This problem occurs due if the following conditions are met:

• The Windows NT redirector write-behind caching mechanism is enabled.
• The network connection is across an inconsistent WAN link.

RESOLUTION

To correct this problem:

WARNING: Using Registry Editor incorrectly can cause serious, system-wide problems that may require you to reinstall Windows NT to correct them. Microsoft cannot guarantee that any problems resulting from the use of Registry Editor can be solved. Use this tool at your own risk.

1. Start Registry Editor (REGEDT32.EXE) and locate the following Registry subkey in the HKEY_LOCAL_MACHINE subtree:

   \SYSTEM\CurrentControlSet\Services\Rdr\Parameters

2. From the Edit menu, select Add Value.

3. Enter the following:

         Value Name: UseWriteBehind
         Data Type:  REG_DWORD
         String:     0
   
   

4. Choose OK and quit the Registry Editor.

5. Shut down and restart Windows NT.

MORE INFORMATION

If the Windows NT caching mechanism is enabled and a file is open with read and write privileges, the Windows NT redirector and Windows NT Cache Manager performs a file write-behind caching. During this process, data is copied from the buffer to the local cache and the application (MSMAIL32) is notified that the writing is complete. When Cache Manager flushes the cached data (after 1 to 3 seconds), the redirector uses the data to write Server Message Block (SMB) requests.

The redirector sends the write-behind cached data if one of the following conditions are met:

• The application closes the file
• The file can no longer be cached
• The application calls the FlushFileBuffers command
• The redirector uses 3 write-behind buffers for the file

1. MSMAIL32 locks the local mailbag file.

2. MSMAIL32 reads the local key and *.MBG file.

3. MSMAIL32 opens the remote INQUEUE3.MBG and INQUEUE3.KEY files.

4. MSMAIL32 writes to the remote Postoffice file.

5. MSMAIL32 updates INQUEUE3.MBG and INQUEUE3.KEY and closes them.

6. MSMAIL32 updates the local *.KEY and *.MBG files.

7. MSMAIL32 removes locks for the local mailbag file.