Cannot Add Mailbox Permissions in a Hybrid environment From OnPrem to O365 (Users do not show up in search) RRS feed

  • Question

  • Hi There,

    We Cannot browse/add mailbox delegation to users in Office 365 from On Premise Hybrid Environment (It does work the other way around however from Office365 to on premise users)

    Essentially, if we open the ECP, navigate on the Enterprise Tab (Not Office 365 Tab) and double click a user with a local mailbox on premise 2013, and then goto 'Mailbox Delegation' we cannot see any hybrid users in Office 365 to add delegation to.

    It does work the other way around (In Office 365 ECP we can add on premise users as permissions)

    Any ideas on what could be wrong?



    Thursday, March 30, 2017 5:26 AM

All replies

  • So it looks like you can't 'search' the usual way in Exchange ECP on prem to add office365 mailboxes for delegating permissions. 

    You have to do it through powershell and then it get's synced up through AADSync using add-mailboxpermission

    Anyone else think this is stupid? What an oversight from Microsoft!!

    Thursday, March 30, 2017 7:26 AM
  • It's the expected behavior, the dialogs in the EAC are restricted to show only particular recipient types. The workaround is indeed to use PowerShell.
    Thursday, March 30, 2017 8:59 AM
  • I completely agree when in a hybrid environment you should be able to select O365 migrated users.  I'm running into this issue now as I slowly migrate users to O365.
    Thursday, March 15, 2018 6:54 PM
  • Hello,

    we've an Exchange 2013CU23/EOL Full-Hybrid. I can see OnLine mailboxes listed only in FullAccess delegation window.

    You've to enable ACLable object synchronization at the Organization level. If you migrated mailboxes to cloud earlier than enabling it and earlier than you updated your Exchange on-premise to any versions higher than CU10, you would need to enable ACLs also at mailbox level via Powershell.

    Follow this article:

    I would also like to see OnLine users listed for "Send on Behalf", but it doesn't work. Have you been able to fix it?

    Tuesday, October 29, 2019 11:53 AM