Below will show you how you can enable SMTP authentication for Microsoft Outlook 2002 :

Microsoft Outlook 2002

1. Launch Outlook.

2. Select Tools > E-mail Accounts...

3. Select View or change email accounts.

4. Click More settings.

5. Select the Outgoing Server tab.

6. Check the My outgoing server (SMTP) requires authentication box. 

    Make sure the Use same settings as my incoming mail server is checked.

7. Click OK button. Click Next. Click Finish.