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Exchange 2010 Room mailbox unable to process meetings for “some” users

I won’t forget how I resolved this one coz I had to spent some quality time and do extensive homework!

Following are some of the troubleshooting steps you may attempt in the event you face an issue as mentioned in the title.


Exchange 2010 Meeting Room mailbox is not accepting the meetings for some users



Change in attribute from outlook to Exchange CAS server.


  1. Verified the meeting room configuration.
  2. Created new meeting room.
  3. Sent from different users.
  4. Run the cmdlet and got the following results.
    Get-mailbox <Identity>| fl *type*,*link*,*share*

    The output was the following:

    ResourceType                 : Room
    RecipientType                 : UserMailbox
    RecipientTypeDetails        : RoomMailbox
    IsLinked                          : False
    LinkedMasterAccount       : NT AUTHORITYSELF
    IsShared                         : False

    Get-CalendarProcessing <Identity> | fl AutomateProcessing

    The output was the following:

    AutomateProcessing      AutoAccept.

    Get-Calendarprocessing <Identity> | fl *policy

    The output was the following:

    RequestOutOfPolicy            :
    AllRequestOutOfPolicy         : False
    BookInPolicy                      :
    AllBookInPolicy                   : True
    RequestInPolicy                  :
    AllRequestInPolicy              : False

  5. Checked for the same user from OWA. It was working but this was not the expectation and customer told me that Add-ins/API are same between 2 computer where one has working user and other has non-working user.
  6. Tried outlook /resetfolders
  7. Restarted the Microsoft Exchange Mailbox Assistants.
  8. Increase the diagnostic logging on MSExchangeMailboxAssistant> Approval assistant and Resource booking attendant to Expert.
  9. Started the Extrace from Exchange 2010 EMC tools for following
    1. MailboxAssistants.Assistants
    2. MailboxAssistants.Assistants.Approval
    3. MailboxAssistants.Assistants.Calendar
    4. MailboxAssistants.Assistants.CalendarNotification
    5. MailboxAssistants.Assistants.CalendarRepair
    6. MailboxAssistants.Assistants.CalendarSync
    7. MailboxAssistants.Assistants.ResourceBooking
    8. Infoworker.Common
    9. Infoworker.Availability
    10. Infoworker.MeetingValidator
  10. Sent a meeting request to the Room mailbox from a problem mailbox.
  11. Stopped the Extrace and analyzed
  12. Found the below error in the Extrace

    MReq SentRepresenting and CalItem SentRepresenting do NOT match.

  13. Now it was sure that some attributes are getting changed in outlook so the suspect was Add-Ins.
  14. Took the remote control of the problem machine and found the below screenshot.

                    15. So the ST in the middle told us that there is something in the middle. The normal meeting windows looks like the window below

                   16. We checked the Add-ins and found IBM Same Time add-in was there.

                   17. We disabled the add-in still no luck.

                   18. We removed this add-in and auto accept started working in the meeting room mailbox.


Extrace will show the issue: MReq SentRepresenting and CalItem SentRepresenting do NOT match.

In this case IBM SameTime Add-in caused the issue and removing the add-in fixed the issue.


If you see the issue where auto accept is working from OWA and not working from Outlook then it is an outlook add-in issue.

You will also find something before meeting as marked in the screenshot then we need to check the add-in and remove it.

Prabhat Nigam (Wizkid)

Keywords: Exchange 2010 room mailbox unable to process requests, exchange 2010 room mailbox not working, Exchange 2010 room mailbox issue, room mailbox not accepting meeting requests

9 Responses to “Exchange 2010 Room mailbox unable to process meetings for “some” users”

  1. Kottees Says:

    Hello Prabhat,

    I like the way you narrow down the issue. Thanks for sharing.

  2. Prabhat Says:

    Thank you Kottees

  3. Chandrakala Says:

    hey its very nice and easy to understand the the issue and resolution. Thank you very much for sharing the same.

  4. Garry Says:

    Wow. Great article.
    This wasn’t exactly my issue but it did point me in the right direction.
    We have a voice mail system integrated with outlook.
    I noticed that the addins for the working system had 3 from the voice mail system,
    But the were missing on the mailboxes that did not work.
    I added that to the fact that when booking the meeting, it referred to the voice mail system as well.

    I de-installed the voice mail program, with it’s add ons. Rebooted. Re-installed it. Re-linked it to the account,
    and it worked!

    Thanks for a great article!

  5. Asim Says:

    It’s very helpful ..and great

  6. Jason Says:

    Nice article. Question, what did you use to read the etl files that are created from the trace? Also, when trying to track down a calendar issue, did you configure “mailbox trace filtering options” for a specific mailbox when troubleshooting the issue?

  7. Prabhat Nigam Says:


    Tracerpt executable is built in app to a server 2008 ent sp1 and above.

    You need ExTrace and after that the following command to convert the output into CSV (better readable format):

    ExTrace -C -V “\trace.etl” > C:\Report.csv

  8. Clive Says:

    Great Article – thanks for posting it .

    I had similar issues with auto processing just stopped . However I found that if the mailbox capacity is full , processing will fail. This would not be immediately obvious especially since the standard room account is disabled.

  9. Frank Says:

    Thanks for your comment. After 2 hours googling around it turned out to be a meeting room mailbox full.

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