PRB: IMS Custom Routing DLL may Drop Mail

ID: Q188298

The information in this article applies to:

Exchange Development Kit (EDK), version 5.0
Microsoft Exchange Server, version 5.5
Microsoft Exchange Server, version 5.5 Service Pack 1

SYMPTOMS

The Exchange Server Internet Mail Service (IMS) when configured to use a custom routing DLL may drop mail if the definition and implementation of the rcRouteInboundMail() uses _stdcall.

CAUSE

For this call, the Exchange server is expecting the caller to cleanup the stack that requires the called DLL to use the _cdecl calling convention. The sample routing DLL uses a _cdecl calling convention that properly reroutes SMTP mail.

MORE INFORMATION

The sample routing DLL is called Imcext.dll and is found on the Exchange SDK as well as the "Microsoft BackOffice Resource Kit: Part One" compact disc. Searching the Microsoft Developer Network on "IMC Sample Extension" returns more information on this sample.

REFERENCES

For additional information, please see the following articles in the Microsoft Knowledge Base:

   ARTICLE-ID: Q178378
   TITLE     : XCON: IMS Does Not NDR Message When Passed DISP_NDR_ORIG

   ARTICLE-ID: Q169681
   TITLE     : XCON: IMS Stops with Access Violation When Using Imcext.dll

Additional query words: kbDSupport kbXchgeSDK kbMsg kbEDK kbdse Xfor kbXchge550

Keywords          : XFOR 
Version           : WINDOWS:5.0,5.5
Platform          : WINDOWS
Issue type        : kbprb

Last Reviewed: March 9, 1999