Answer to your second question is yes, some people in a domain set their login credentials for windows to authenticate their email in outlook because they are the same, so that when a user logs in and opens outlook it is automatically the outlook of whichever windows user has logged in. This is instead of storing your authentication in outlook settings. If your company uses an exchange server to do email then this would be the ideal way to set it up. If not try this(may be different for 2012 but same basic principle):

Dave's Answer:

Select Tools -> E-mail
Accounts menu option. (depending on your version of Outlook this option might be found under Tools -> Options -> Mail

Setup tab -> E-mail Accounts button)

1. The "View or change existing e-mail accounts" item should be already selected. Click "Next".
2. Select the account you want to modify and click "Change".
3. In the next screen, click "Remember password" in the "Logon Information" section in the lower left corner.
4. Then click "Next" or "OK" as necessary to confirm.