PRB: Problems with CoInitializeEx and CDO (239096)


The information in this article applies to:

  • Microsoft Exchange Server 5.5
This article was previously published under Q239096

SYMPTOMS

Collaboration Data Objects (CDOs) are not multi-threaded apartment safe. The COM library has to be initialized as a multi-threaded apartment to make CDO a multi-threaded apartment. From CDO, the MAPIInitialize function is called, which in turn calls the CoInitialize(NULL) function. This causes a conflict and the code fails.

MORE INFORMATION

The following sample code fails with error code 0x80040154 (REGDB_E_CLASSNOTREG): 

#define _WIN32_DCOM

#import <cdo.dll> no_namespace

#include <stdio.h>
#include <assert.h>
#include <tchar.h>
#include <objbase.h>

#pragma message ("TO DO: change RECIPIENT_NAME to your emailid")
#define RECIPIENT_NAME "jack@microsoft.com"

void dump_com_error(_com_error &e)
{
    _tprintf(_T("Oops - hit an error!\n"));
    _tprintf(_T("\a\tCode = %08lx\n"), e.Error());
    _tprintf(_T("\a\tCode meaning = %s\n"), e.ErrorMessage());
    _bstr_t bstrSource(e.Source());
    _bstr_t bstrDescription(e.Description());
    _tprintf(_T("\a\tSource = %s\n"), (LPCTSTR) bstrSource);
    _tprintf(_T("\a\tDescription = %s\n"), (LPCTSTR) bstrDescription);
}

struct StartOle {
    StartOle()  {
         CoInitializeEx(NULL,COINIT_MULTITHREADED) ;	
    }

    ~StartOle() {
         CoUninitialize();
    }
} _inst_StartOle;

void main()
{
    try {
	
        SessionPtr pSession("Mapi.Session");
        pSession->Logon("Microsoft Outlook");

        FolderPtr   pFolder = pSession->Outbox;
        MessagesPtr pMessages = pFolder->Messages;
        MessagePtr  pMessage = pMessages->Add();
        pMessage->Subject = "VCCOM: MAPI Example";
         
        RecipientsPtr pRecipients = pMessage->Recipients;
        RecipientPtr pRecipient = pRecipients->Add();
        pRecipient->Name = RECIPIENT_NAME;
        pRecipient->Type = (long) mapiTo;
        pRecipient->Resolve();

        pMessage->Send(false, false);
        pSession->Logoff();

        } 

catch (_com_error &e) {
        dump_com_error(e);
    }
}

Workaround

To solve the problem, change the following registry key from Both to Apartment: 

HKEY_CLASSES_ROOT\CLSID\{3FA7DEB3-6438-101B-ACC1-00AA00423326}\InprocServer32\ThreadingModel

REFERENCES

For additional information, click the article number below to view the article in the Microsoft Knowledge Base:

239853 MAPI_NO_COINIT Flag To Make MAPIInitialize Not Call CoInit

Modification Type:MinorLast Reviewed:3/4/2004
Keywords:kbfix kbprb KB239096
©2004 Microsoft Corporation. All rights reserved.