How to Setup SMTP Authentication in Incredimail
Open Incredimail.
From the main screen open the the 'Tools' menu.
Click on Accounts from the drop down window.

Next, highlight the redred.com account and click on the Properties button.

Click on the tab labeled Servers.
Check the box labeled My server requires authentication.

Click 'OK' to close this window.
Click 'Close' to close the previous window.
Done!