MAPI COM Surrogate processes left by Task Scheduler without a desktop session

Question

MAPI COM Surrogate processes left by Task Scheduler without a desktop session

Dave 206

I have an application that uses MAPI for email work. I have set up this application to run in Task Scheduler.

If I run this task with Run whether the user is logged on or not then the task leaves zombie COM Surrogate processes running after the task is finished.

If I leave this user logged in and run this task with Run only when the user is logged on then I don't get these COM Surrogate processes accumulating.

Why would MAPI and Outlook create these COM Surrogate processes when the user isn't logged in and how do I get it to clean up the task properly? I'd prefer not to require this logon session as it'll fail the process after the server reboots.

PS. I posted this also as https://learn.microsoft.com/en-us/answers/questions/2101658/zombie-com-surrogate-(wininetcacheserver)-processe but I've since discovered it's related to a desktop session, so asking a simpler question.

Dave 206

When I view a memory dump of these COM Surrogate processes I always see the same two call stacks, although sometimes there are more than the two shown threads:
User's image

main thread:

ntdll.dll!NtWaitForSingleObject()
KERNELBASE.dll!WaitForSingleObjectEx()
combase.dll!CSurrogateProcessActivator::WaitForSurrogateTimeout() Line 2009
	at onecore\com\combase\dcomrem\surract.cxx(2009)
combase.dll!CoRegisterSurrogateEx(const _GUID & rguidProcessID, ISurrogate * pSrgt) Line 447
	at onecore\com\combase\dcomrem\surract.cxx(447)
dllhost.exe!wWinMain()
dllhost.exe!__scrt_common_main_seh()
kernel32.dll!BaseThreadInitThunk()
ntdll.dll!RtlUserThreadStart()

Other thread:

win32u.dll!NtUserGetMessage()
user32.dll!GetMessageW()
combase.dll!CDllHost::STAWorkerLoop() Line 1277
	at onecore\com\combase\objact\dllhost.cxx(1277)
combase.dll!CDllHost::WorkerThread() Line 1206
	at onecore\com\combase\objact\dllhost.cxx(1206)
combase.dll!CRpcThread::WorkerLoop() Line 282
	at onecore\com\combase\dcomrem\threads.cxx(282)
combase.dll!CRpcThreadCache::RpcWorkerThreadEntry(void * param) Line 76
	at onecore\com\combase\dcomrem\threads.cxx(76)
kernel32.dll!BaseThreadInitThunk()
ntdll.dll!RtlUserThreadStart()