Configuration of both versions are identical.
First select item "Accounts..." from "Tools" menu, like on the picture below.
Then a window will appear:
Select "Mail" tab, select your mail account and press the "Properties" button. Another window will appear:
Select "My server requires authentication" and press the Settings button to configure it further. Another window will appear:
If you want to use the same login/password that you are using for pop then select "Use same settings as my incoming mail server". If you want to specify another pair, then select "Log on using" and fill the "Account name" and "Password" fields. Press OK, to close the window, press OK again and again and now you have fully configured Outlook Express.