PRB: GetMessage Returns Message Object Instead of MeetingItem

ID: Q196258

The information in this article applies to:

Collaboration Data Objects (CDO), version 1.1
Microsoft Exchange Server, version 5.5

SYMPTOMS

When you use the Exchange Scripting Agent to accept or decline meeting requests programmatically, the following line of code might return a Message object instead of a MeetingItem object:

   Set oMtg = EventDetails.Session.GetMessage(EventDetails.MessageID, Null)

For example, if you use AutoAccept script, the following log might be added into the script log when a meeting item (that is, a meeting request or meeting response) arrives:

   Message is not a meeting request or response.

CAUSE

The Event Scripting Agent might be using an earlier version of CDO library. In this case, the Class property of the Message object returns 3 (for a Message) instead of 26 (for an AppointmentItem).

This might happen if you install Microsoft Outlook 97 after you install Microsoft Exchange Server on the same computer and you stop or start Microsoft Exchange Event Service.

When you install Microsoft Outlook 97, Outlook 97 installs and registers an earlier version of CDO, that is, the Active Messaging Library (OLEMsg32.dll). The Active Messaging Library (CDO 1.1) does not support meeting items. Therefore, the GetMessage method of the Session object returns a Message object instead of a MeetingItem object.

RESOLUTION

Follow these steps to resolve the problem:

1. Re-register CDO.dll by typing the following line at the MS-DOS command

   prompt:

      regsvr32.exe cdo.dll

2. Go to Control Panel, and click Services.

3. Stop and start Microsoft Exchange Event Service.

STATUS

This behavior is by design.

MORE INFORMATION

To see what version of CDO that the Event Scripting Agent is using, use the Version property of the Session object (EventDetails.Session.Version).

REFERENCES

The following article in the Microsoft Knowledge Base explains another possible cause for getting the incorrect Message.Class from GetMessage method:

    ARTICLE-ID: Q194806
    TITLE     : PRB: Message.Class Incorrect After Calling GetMessage()

Additional query words:

Keywords          : kbActMsg kbCDO kbCDO110 kbXchge550 kbMsg 
Version           : WINDOWS:1.1; WINNT:5.5
Issue type        : kbprb

Last Reviewed: November 25, 1998