Please follow the detailed instructions with screenshots below for setting Incredimail up to work with turboSMTP.
1 - Open Atomic Mail, go to "Common Settings" in the "Settings" menu, and click on the "SMTP" label. Then choose "External SMTP only":
2 - Click on the "+" icon to add another SMTP server. The following window will appear:
3. Enter the following parameters:
4. Click OK and save the settings.