May 27, 2014

Office 365 - Shared mailboxes auto-mapping

Exchange On-premises to Office 365 post migration auto-mapping issue:

Here is msExchDelegateListLink attribute that is being populated when you grant full access to mailbox.This attribute is responsible for auto-mapping shared mailboxes in users outlook.
If you migrate mailbox to Office 365 this attribute is migrated as well according to

In Office 365 (if we connect remotely using we couldn't manage msExchDelegateListLink attribute due to Office 365 limitations.

As result we can't disable or manage auto-mapping for mailbox changes that took place before migration.

When we run "Get-MailboxPermission" we do not see any permission entires for but shared mailbox is still showing up in users outlook.

If we need to remove auto-mapping (as result remove Full Access permission) for from we have to grant permission first and then remove it.

Add-MailboxPermission -User -AccessRights FullAccess -InheritanceType All
Remove-MailboxPermission -User -AccessRights FullAccess -InheritanceType All

Also it worth to check mailbox folder permissions in case if you provided permissions for mailbox internally:

Remove-MailboxPermission -User -AccessRights FullAccess -InheritanceType All


  1. You're da man!

  2. Thank you! Very helpful for my exchange management and troubleshooting.