Delegate mailbox won't open?

Question

I am trying to open a delegated Outlook mailbox in Outlook web. When I click on "open another mailbox" this message appears. I have full delegate access.

Answer 1

Dear DalyPA,

Good day! Thank you for posting to Microsoft Community.

In order to understand your query and provide possible solution, May I please double confirm if you tried to clear your browser cache and cookies? if not, clear your browser cache and cookies, then try again.

• May I please know if you waited some hours after the mailbox is assigned a delegate permission?
• May I please double confirm if the delegate permission is assigned through Microsoft Admin center or Outlook? Make sure you have the correct permissions to access the delegated mailbox.
• May I please double confirm if you tried to access the delegated mailbox from a different browser or device to see if the issue persists?
• Ensure that the delegated mailbox is not hidden from the address book. If it is, you will need to unhide it before you can access it.
• You may try to remove and re-adding the delegate permission to see the difference.

I look forward to your response. Kindly note that the above requested information is required for further analysis and troubleshooting of your situation. Your patience and cooperation are much appreciated.

Thank you for your precious time. Have a nice day.

Sincerely,

Libeamlak | Microsoft Community Moderator

Answer 2

Hello DalyPA,

Good day. Thank for posting in the community.

We've received your query, and you can expect to receive response from one of our community moderators accordingly.

At this point, we appreciate your patience and cooperation. Thank you.

Sincerely,

Community moderator