To add another mailbox to Outlook, you must first submit a Help Desk ticket to request access if you have never accessed the mailbox before. Then proceed with the following:

1. Open Outlook
2. Click the "FILE" menu
3. Click the "Account Settings" button and choose "Account Settings..."
4. On the "E-mail" tab, Select your existing email account, click "Change..."
5. Choose "More Settings.."
6. Choose "Advanced"
7. Choose "ADD" and enter the name of your additional account
8. Click "OK"
9. Click "Next"
10. Click "Finish"
11. Restart Outlook