The following steps were created using Microsoft Outlook 2000 SR-1 Corporate/Workgroup Edition. If you have another version of Outlook 2000 (e.g., Internet Mail Only), you may need to go to Configuring Microsoft Outlook Express. (Go to Help/About Outlook to determine which mode outlook is configured in.)
First select item "Services" from "Tools" menu, like on the picture below.
Then a window will appear:
Select your mail account and press the "Properties" button. Another window will appear:
Select the "Servers" tab.
Select "My server requires authentication" and press the Settings button to configure it further. Another window will appear, Select the "Use same settings as my incoming mail server" radio button. Press OK, to close the window, press OK on the remaining windows. You have now fully re-configured Outlook.