Import e-mail addresses from a text file into Outlook
To import the contacts into Outlook 2000 you can do the following:
Create a new folder under contacts that will store the imported contacts. With the folder selected, click on File > Import and Export and then select 'Import from another program or file'. Select 'Comma Seperated Values' or 'Tab Seperated Values'. Outlook may prompt you to install this feature before proceeding. Select the file to import and set it to replace duplicates. Select the folder you wish to import the contacts to (it should be the same folder you had selected).
Click on the checkbox beside 'Import [...]'. A new window will pop up allowing you to assign each field in the text file to a field in Contacts. Drag the field from the left to the field of choice on the right. The item you dragged should now appear to the right of that field. Once everything is mapped, click Okay.
One quick note, Outlook expects the first line in the text file to have the field names. If your entries start at Line 1 and do not include field names, then I recommend adding them in.
If you're using another version of Outlook, I suspect the process should be similar.