Enabling SMTP authentication
1. Open Outlook 2007
2. From the Tools menu select Account Settings. The Account Settings box appears.
3. Verify that the E-mail tab is selected. Your email account appears, usually labeled mail.yourdomainname.
4. Click on the account to highlight it, and click on the Change icon above it. The Internet E-mail Settings appear.
5. Under the Server Information section, in the box marked Outgoing mail server (SMTP) change the entry to your mail server.
6. Click the button More Settings… in the lower right-hand corner. The Internet Email Settings box appears.
7. Click on the tab Outgoing Server.
8. Click the check box My outgoing server (SMTP) requires authentication, and verify that the circle-box Use same settings as my incoming mail server is selected.
9. Click OK to close the Internet Email Settings box.
10. IMPORTANT: Do NOT use the “Test Account Setting…” button to test the settings. This will fail.
11. Click the Finish button to close the Internet E-mail Settings box. Click the Close button to close the Account Settings box. SMTP authentication has now been enabled.