1. The shared mailbox does not appear at all
Work through these in order:
- Check you have Full Access permission, not just Send As. Send As lets you send from the address; Full Access is what lets you open the mailbox.
- Give it time, then restart Outlook. New permissions are not always picked up immediately; closing and reopening Outlook after a short wait is often all it takes.
- Check automapping. In classic Outlook for Windows, a mailbox you have Full Access to is added automatically. If the permission was granted with automapping switched off, it will not appear by itself — add it manually instead.
- Add it manually: File → Account Settings → Account Settings, select your account, Change → More Settings → Advanced → Add, and type the shared mailbox’s name.
In Outlook on the web, right-click Folders and choose Add shared folder or mailbox. The new Outlook for Windows has the same option — though remember the new Outlook only supports Exchange Online mailboxes, not Exchange Server or hosted Exchange (see our guide to the new Outlook). On a Mac or a phone, see how to add a shared mailbox on Mac, iPhone and Android.
2. It shows, but new mail does not appear
This is almost always cached Exchange mode. By default, Outlook downloads a local copy of shared folders as well as your own mailbox, and that copy can fall behind.
- Go to File → Account Settings → Account Settings, select your account, Change → More Settings → Advanced.
- Untick Download shared folders.
- Restart Outlook. The shared mailbox is now read live from the server.
The trade-off is that the shared mailbox needs a connection to work, and searching it can be slower. For most offices that is a price worth paying for a mailbox that is always up to date.
3. Search does not find anything in the shared mailbox
Searching a shared mailbox depends on how it is opened. When it is cached locally, search relies on the PC’s index, which can be incomplete. Opening it online — the same Download shared folders setting above — means searches run on the server instead. Outlook on the web always searches on the server, which makes it a useful way to check whether a message is really missing or just not indexed.
4. Sent messages end up in my own Sent Items
By design, when you send as a shared mailbox, Exchange saves the copy in your Sent Items — so colleagues cannot see what was sent from the shared address. An administrator can change that so a copy is also saved in the shared mailbox’s own Sent Items. On Exchange Server and Exchange Online that is a mailbox setting; if you are a MyExchangeServer customer, ask us and we will set it for you.
5. The signature is wrong or missing
Outlook signatures belong to the person, not the mailbox. When sending from a shared mailbox, choose the right signature from Insert → Signature in the message, or create one specifically for the shared address. For consistent branding across everyone, a server-side signature tool is the more reliable answer.
6. It worked, then disappeared
- Permissions changed — someone removed and re-added your access, perhaps with automapping off.
- A new Outlook profile was created, and the manually added mailbox was not added back.
- Too many people are using it. Microsoft advises no more than 25 users on one shared mailbox; beyond that, connection failures and duplicates appear. A larger team is better served by a group.
Shared mailbox or something else?
If the real need is “everyone gets a copy”, a distribution list may suit better than a shared mailbox — our answer page on shared mailboxes vs distribution lists explains the difference. And if you are wondering whether shared mailboxes cost extra, see our guide to shared mailbox licensing.
On MyExchangeServer, shared mailboxes are free and your own team can create them and set permissions in the SolidCP control panel.