For "Outgoing mail server (SMTP)", please key in (without quotes) "smtp.mydomain-name.com".
For example, if your domain name is "signetique.com", you will key in "smtp.signetique.com".
Click "More Settings..."

Tick the box "My outgoing server (SMTP) requires authentication".
Choose "Use same settings as my incoming mail server".

Click "Next".

Click "Finish".