On-premises Exchange 2016 + Office 365 (latest) Shared mailbox issue.

Copper Contributor



I'm having a strange issue with office 365 (latest) & Exchange 2016.


I've shared one users mailbox (User A) with another (User B) and visa versa. Both have Full access to each other's mailboxes.


When I open outlook on User B, automapping does not occur. If I go to Account settings, and manually add User A's mailbox - it appears below user B's mailbox - but the contents is exactly the same as that of user B's mailbox. Also - if I close Outllook and re-open it - it's gone, but still there under account settings.


In Outlook 2013 - everything works as expected.


Please help, 





1 Reply



Most of the permission issues are resolved by removing the permission and re-adding them via PowerShell automapping true.

Add-MailboxPermission -Identity userA -User userB -AccessRights FullAccess -InheritanceType all -AutoMapping $True