1. Open Outlook 2010 and click File > Info > Account Settings
  2. Highlight the account and click Change
  3. Click More Settings
  4. Click on the Advanced Tab then click Add
  5. Type the name of the account or mailbox address and click OK
  6. Verify the new mailbox is listed, then click OK to save
  7. Click Next
  8. Click FinishCongratulation! You have successfully entered all the information required to setup the new account
  9. Click Close
  10. The new Mailbox will be listed below your primary account