Can't open Shared mailbox on mobile device, works on every other client.

Anonymous
2021-06-15T13:20:37+00:00

We want to share mailboxes with 'Least privilege' principle.

So when creating a shared mailbox instead of making users Owner we want to assign only permissions on the necessary folders.

With a PowerShell session to Exchange Online we make the following changes:

Add-MailboxFolderPermission -Identity SharedMailboxTest:\ -user ******@contoso.com -AccessRights Reviewer

Add-MailboxFolderPermission -Identity SharedMailboxTest:\Inbox -user ******@contoso.com -AccessRights Reviewer

This works fine with Outlook Web App and Outlook desktop client. We can add the shared folder and read the messages.

But when we try to add a shared folder on a Outlook Mobile client we get an error:

Authentication failed

That didn't work. You may not have the right permissions to add this mailbox or this mailbox doesn't exist.

Also added permission directly on the mailbox:

Add-MailboxPermission -Identity SharedMailboxTest -User ******@contoso.com -AccessRights ReadPermission

But that didn't make a difference.

It must be possible to delegate folder permissions. It works for default clients, but it refuses to work on mobile Outlook unless I give the user Owner permissions, but that is not 'Least privilege'.
What I'm I missing here or did I stumble on a bug in Outlook Mobile?

(It has to be Outlook mobile client on cell phones)

Outlook | Windows | Classic Outlook for Windows | For home

Locked Question. This question was migrated from the Microsoft Support Community. You can vote on whether it's helpful, but you can't add comments or replies or follow the question.

0 comments

48 answers

Sort by: Oldest
Most helpful Newest Oldest
  1. Anonymous
    2021-09-10T15:38:20+00:00

    same issue here, please fix asap

    Was this answer helpful?

    0 comments
  2. Anonymous
    2021-09-10T15:47:24+00:00

    I have same problem.

    I try install old version of Outlook apk. But problem still persist. I try disconect from Intune and configure Outlook, but problem still persist.

    The shared mailbox in the mobile app worked properly. Unfortunately, I needed to test something, so I deleted my Outlook data, then re-added my account, and I can't add a shared mailbox in any way.

    Was this answer helpful?

    1 person found this answer helpful.
    0 comments
  3. Deleted

    This answer has been deleted due to a violation of our Code of Conduct. The answer was manually reported or identified through automated detection before action was taken. Please refer to our Code of Conduct for more information.

    Comments have been turned off. Learn more

  4. Anonymous
    2021-09-10T17:33:53+00:00

    For the interested folks.

    This is the answer I got from Microsoft. They are planning to release a fix on Sept. 10th 2021 at 8:30PM UTC (4:30PM EST)
    ________________________________________________________________________________
    Title: Users can't add shared mailboxes via the Outlook mobile app

    *User Impact: Users are unable to add shared mailboxes via the Outlook mobile app.**More info: Outlook desktop and Outlook on the web are unaffected.Users will encounter the following error when attempting to add shared mailboxes via the Outlook mobile app:"Authentication Failed: That didn't work. You may not have the right permissions to add this mailbox or the mailbox doesn't exist."**Current status: We've determined that the reversion of the offending change across the affected environments requires additional validation and processing time, and we now anticipate resolution by Friday, September 10, 2021.**Scope of impact: Any user attempting to add shared mailboxes via the Outlook mobile app may be impacted.Start time: Tuesday, August 24, 2021, at 7:00 AM UTCEstimated time to resolve: We expect the change will be reverted and the user impact will be mitigated by Friday, September 10, 2021.*Root cause: A recent update intended to optimize the error code for disabled accounts incidentally introduced an incorrect logic and caused impact. Next update by: Friday, September 10, 2021, at 8:30 PM UTC

    Was this answer helpful?

    10+ people found this answer helpful.
    0 comments
  5. Anonymous
    2021-09-11T17:31:18+00:00

    Any update on this? It's now September 11th and this is still not working. This is business critical for us.

    Was this answer helpful?

    2 people found this answer helpful.
    0 comments