Even though you had Full Access, Outlook didn’t show the shared mailbox because auto‑mapping failed. In this video, I’ll show you exactly how to fix it.
Identify what shared mailboxes actually are and permissions.
- Go to Microsoft 365 admin center > Teams & groups > Shared mailboxes. Confirm shared mailbox membership and Full Access
- Attach the shared mailbox to test in Outlook Web. Login Outlook Web, click 3 dots next to the mailbox. Click add shared folder or mailbox. Enter the mailbox name. click confirm.
- Add the shared mailbox in Outlook Desktop (permanent mapping). In Outlook Desktop → File → Account Settings → click Account Settings again→ Change → More Settings → Advanced. Under Open these additional mailboxes, click Add…
2
Confirm shared mailbox membership and Full Access
Already Correct
We verified that Kristi is a member and has Full Access to the CLAIMS mailbox.
Microsoft 365 Admin Center → Teams & groups → Shared mailboxes → CLAIMS
- Go to Teams & groups → Shared mailboxes and select CLAIMS
- Under Members, you saw: test
- Click Manage mailbox delegation / permissions
- In Full Access (Read and manage), you confirmed Kristi is listed
- In Send as, test is also listed (optional but good)
- This proves permissions are correct; the issue is Outlook not auto‑mapping the mailbox
3
Open CLAIMS directly in Outlook Web to verify mailbox health
We checked that the CLAIMS mailbox itself works and is not a storage or corruption issue.
Outlook Web → Open another mailbox
- In Outlook Web, use profile picture → Open another mailbox
- Enter claims@abc.com and open it
- You saw the CLAIMS inbox with recent mail, proving:
- The mailbox is healthy
- It is not out of space
- It can send/receive normally
- This confirmed the problem is Outlook profile mapping, not mailbox health
4
Attach the shared mailbox to test in Outlook Web
Makes It Stick
We added the shared mailbox to test’s profile so it appears in her folder list, not just in a separate tab.
Outlook Web → Settings → View all Outlook settings → Mail → Accounts → Shared mailboxes
- In tst’s Outlook Web, go to Settings (⚙️) → View all Outlook settings
- Navigate to Mail → Accounts → Shared mailboxes
- Click Add shared mailbox
- Enter claims@abc.com (and repeat for info@abc.com)
- After saving and refreshing, CLAIMS and INFO appear in the left folder pane under test’s mailbox
- This forces Outlook to treat them as attached shared mailboxes
5
Add the shared mailbox in Outlook Desktop (permanent mapping)
Desktop Fix
We ensured the same shared mailboxes appear in Outlook Desktop by adding them as additional mailboxes.
Outlook Desktop → File → Account Settings → Account Settings → Change → More Settings → Advanced
- Open Outlook Desktop on Kristi’s PC
- Go to File → Account Settings → Account Settings
- Select test@abc.com and click Change…
- Click More Settings…, then go to the Advanced tab
- Under Open these additional mailboxes, click Add…
- Enter claims@abc.com (repeat for info@abc.com)
- Click OK → Next → Finish, then restart Outlook
- CLAIMS and INFO now appear permanently in the left folder pane as full mailboxes