Accessing shared email account from Outlook app

Dear @nik,

I understand that you already have access to the shared mailbox, but Outlook for Mac returns the issue message: “Cannot open account. We encountered an error while adding account. Please try again.” when adding it through Delegates and Sharing > Shared With Me. Open a shared Mail, Calendar or People folder in Outlook for Mac | Microsoft Support

Please first confirm that the mailbox is a Microsoft 365/Exchange shared mailbox and that your account has been granted Full Access / Read and Manage permission. Outlook for Mac supports shared mailbox access best when Full Access permission is assigned. If you also need to send from the mailbox, the administrator should also assign Send As or Send on Behalf permission. Create a shared mailbox - Microsoft 365 admin | Microsoft Learn

As a workaround, please try opening it through File > Open > Shared Mailbox in Outlook for Mac. If that does not work, try adding it as an additional Exchange account by entering the shared mailbox email address and signing in with your own Microsoft 365 credentials when prompted.

Please also test whether you can open the shared mailbox in Outlook on the web. If it works on the web but not in the Outlook Mac app, the issue is likely local to the Outlook profile or cached account data. In that case, please update Outlook for Mac, restart the app, and if needed create a fresh Outlook profile, add your main mailbox first, then add the shared mailbox again.

If the shared mailbox cannot be opened in Outlook on the web either, the Microsoft 365/Exchange admin should remove and re-add the Full Access permission for your account and then test again.

I hope the information shared helps point you in the right direction. Please try the steps above and let me know if they work. If not, we can continue working together to narrow this down.

The first response may not always resolve the issue right away, but with your help and more details, we can work toward a solution.

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