2: Click Change
3: Click More Settings
4: Click Advanced Tab then Click Add
5: Type in name of additional / secondary mailbox and Click OK
Note: You must have at least READ access to new mailbox otherwise after adding, you will not be able to open new mailbox. If you need help with this, ask your systems administrator
6: Verify new Mailbox is listed under “Open these additional mailboxes“ Click OK
7: Click Next
8: Click Finish
9: Click Close
That’s it!
Ex-Shell 