Problems Using the Exchange based MS Mail MTAs

In Exchange 4.0sp2 there appears to be a limit of 6 instances of the MTA on a server. I believe that the issue is heap space (see the system messages below). On the server in question, I had a "plain" installation of Windows NT 3.51sp5 (TCP/IP only) with Exchange 4.0sp2 layered onto it, but no additional services.

Others have run into the same symptoms ( and reported it as an error 2186 - see below) when running a large number of non-exchange related services. The common element is the USER32 message, even though the actual DLL that fails may be different.

Message boxes:

Title:	        async.exe - DLL Initialization Failed
Msg Text:	Initialization of the dynamic link library
		C:\WINNT\system32\USER32.dll failed.  The
		process is terminating abnormally.

The service continues trying to start for a minute or two then returns another dialog box:

Could not start the MS Exch Postoffice MTA service on \\EXCHANGESERVER.
Error 2186: The service is not responding to the control function.