Unable to accept a meeting invitation for a room mailbox by using Outlook if the delegate is a shared mailbox

Consider the following scenario.
  • You add a shared mailbox as a delegate for a room mailbox by running the following PowerShell command:
    Set-CalendarProcessing room -ResourceDelegates sharedmbx -AllBookInPolicy $false -AllRequestInPolicy $true
  • When a user tries to accept the meeting invitation from the Inbox of the shared mailbox in Microsoft Outlook, they receive an error message that resembles the following: 
    Cannot open the Calendar folder for user "room alias". The operation failed.

  • The user is able to accept the meeting request from the Inbox of the shared mailbox in Outlook on the web. However, the user who sent the meeting request doesn't receive an email message that confirms that the meeting was accepted. 
This behavior is by design. Users who have access to the shared mailbox don't inherit permissions to the calendar of the room mailbox. 
Users who have full access permission to the shared mailbox must have explicit editing permissions to the calendar of the room mailbox. To assign editing permission to users for the calendar of the room mailbox, follow these steps:
  1. Do one of the following, as appropriate for your situation:
  2. Run the following command:
    Add-MailboxFolderPermission -Identity room@contoso.com:\Calendar -User ed@contoso.com -AccessRights Editor
    Note In this command, replace room@contoso.com with the email address of the room and replace ed@contoso.com with the email address of the user who has full access permissions to the shared mailbox.
Still need help? Go to the Office 365 Community website.

Article ID: 3191290 - Last Review: 09/09/2016 22:33:00 - Revision: 1.0

Microsoft Exchange Online, Outlook 2016, Microsoft Outlook 2013, Microsoft Outlook 2010

  • o365e o365m o365022013 o365 o365a KB3191290