MAPI Property "PidTagDisplayTypeEx" always returns "0x40000000" RRS feed

  • Question

  • Hello,

    I want to reliably determine if added meeting attendee (Required/Optional/Resource type) is conference room or not. And for that I have tried MAPI property "PidTagDisplayTypeEx" as per below 2 articles. 

    However, for conference room type attendee as well I am getting hexa value 0x40000000 (1073741824). As per below article it should be ((ULONG) 0x00000007) OR ((ULONG) 0x00000008). In my case for all the kind of attendees getting 0x40000000.



    Any idea why i am getting 0x40000000. Could it be due to exchange server setting or wrong AD data for conference rooms ? 

    I think Active Directory has below setting for conference rooms which looks correct to me. 

    msExchResourceDisplay: Room; 




    Thursday, May 18, 2017 11:11 AM

All replies

  • Hi Manoj,

    How did you view the MAPI property "PidTagDisplayTypeEx" for the meeting request?

    I tried to view a meeting item properties with MFCMAPI.exe, but there is no PidTagDisplayTypeEx properties. Could you please provide the detailed steps so that we can follow it for further troubleshooting?

    >>I want to reliably determine if added meeting attendee (Required/Optional/Resource type) is conference room or not.

    Generally, if the attendee is a conference room, it would be automatically regarded as Resource in the meeting request. Is there any problem when you add the room for a meeting?


    Winnie Liang

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    Friday, May 26, 2017 7:23 AM
  • Hi Winnie,

    Thanks for your reply!

    using PropertyAccessor I am trying to check MAPI property value. Please see below code. 

    If conference room is been added as a Resources we can identify but what if it has been added as a Required attendee OR required attendee has been added as a Resources to use BCC feature in meeting.

    That's why i want to confirm the attendee type (resources or actually attendee) regardless the field it has been added. 

    Please refer below link where it's mentioned about this property accessor approach to achieve this.


    const string PidTagDisplayTypeEx = @"http://schemas.microsoft.com/mapi/proptag/0x39050003"; foreach(recipient rec in meetingRecipients) {   var recipientType = rec.PropertyAccessor.GetProperty(PidTagDisplayTypeEx);       //always getting 1073741824 (0x40000000) for all the type of attendees (resources & internal to the firm contacts) 

    //As per articles i have added before this value should be different for different attendee types

    //so we can confirm whether added attendee is resource type or real attendee.  }




    Thursday, June 1, 2017 10:26 AM