Classic Outlook (Windows)
1. Open Outlook and select the File tab.
2. Click Account Settings, then select Account Settings from the dropdown menu.
3. Ensure your email address is highlighted and click Change.
4. Click the More Settings button in the bottom-right.
5. Go to the Advanced tab and click Add.
6. Type the email address of the shared mailbox and click OK.
7. Click Apply, then OK, and restart Outlook.
"New" Outlook (Windows/Web)
1. Select Mail from the left-hand navigation pane.
2. Right-click on your primary account name.
3. Click the three ellipsis (. . .) and select Add shared folder or mailbox.
4. Type the email address of the shared mailbox and click Add.
5. The mailbox will appear under the Shared with me folder in the left pane.
Outlook for Mac
1.Go to Tools on the top menu bar and select Accounts.
2. Select your M365 account and click Delegates & Sharing.
3. Select the Shared with Me tab.
4. In the "Open these additional mailboxes" section, click the + (plus) icon.
5. Enter the shared mailbox email address and click Add
