Shared mailboxes (like sales@, support@, info@) are mailboxes multiple people can access without each having a separate account. You need permission first, then it's a quick setup.

1. Confirm you have permission

Your manager or IT must grant access. Without permission, your Outlook can't add the mailbox.

To check: try adding it (next step) — if it fails with "you don't have permission", contact IT.

2. Auto-mapped in Outlook desktop

If you're already granted Full Access, the mailbox usually appears automatically in your Outlook in 15-30 minutes after permission is granted. Look for it in the folder list, expanded below your own mailbox.

If it doesn't auto-appear after 30 minutes:

  • Close Outlook fully (Task Manager → End any OUTLOOK.EXE processes)
  • Reopen

3. Manually add it

If auto-mapping is disabled or you want to add it manually:

  1. File → Account Settings → Account Settings
  2. Click your account → Change → More Settings
  3. Advanced tab → Add → type the shared mailbox address → OK
  4. Finish, close all dialogs, restart Outlook

The shared mailbox appears as a separate folder tree.

4. On the web

outlook.office.com lets you open shared mailboxes:

  1. Right-click your own name at the top of the folder list
  2. Add shared folder or mailbox
  3. Type the shared mailbox address

It appears in the sidebar.

Alternatively, browse directly to: https://outlook.office.com/mail/<shared-mailbox-address>

5. Send as the shared mailbox

When sending from the shared mailbox, you need Send As or Send on Behalf permission separately from access. To use:

  • Open a new email
  • In the From field (View → Show From if hidden), pick the shared address
  • The sent email shows as from the shared mailbox

If From doesn't show the shared address, you don't have Send permission — request it.

6. Send-on-behalf vs. send-as

  • Send As — the email appears to come purely from the shared mailbox
  • Send on Behalf — appears as "Your Name on behalf of Shared Mailbox"

Send As is preferred for customer-facing addresses (no internal info exposed).

7. Calendar of a shared mailbox

If the shared mailbox has a calendar (common for reception or meeting rooms):

  • In Outlook calendar view: Add Calendar → From Address Book → search the shared mailbox

8. Managing folders

Be careful — actions in a shared mailbox affect everyone using it:

  • Don't move messages to your own folders accidentally
  • Use shared mailbox subfolders for organization
  • "Read/unread" status is per-user in M365 (so marking as read for you doesn't mark it for others)

9. Out of office on a shared mailbox

Setting OOO on a shared mailbox:

  • Web only: open the shared mailbox in OWA → Settings → Automatic replies
  • Outlook desktop doesn't let you set OOO on shared mailboxes; use the web

10. Mobile

Adding a shared mailbox to the Outlook mobile app:

  • iOS: Settings → Add Mail Account → Add Shared Mailbox
  • Android: tap your account avatar → + → Add Shared Mailbox

When to ticket

Raise a ticket if:

  • You can't access a shared mailbox you should have access to
  • The mailbox isn't appearing despite waiting 30+ minutes after access was granted
  • You need Send As / Send on Behalf permission added
  • You need a new shared mailbox created