Setting Mozilla
Click "Edit", then "Mail and Newsgroups Account Settings...".

Click "Outgoing Server (SMTP)".
For "Server Name", please key in (without quotes) "mail.mydomain-name.com". For example, if your domain name is "signetique.com", you will key in "mail.signetique.com".
Tick "Use name and password".
For "User Name", please key in your email address. For example, if your email address is "support@signetique.com", then you key in (without quotes) "support@signetique.com".

When you are sending out your mail, you will be prompted for a password. Key in the pass that you use for checking your mails. Click "OK".