Check out
http://products.secureserver.net/email/email_thunderbird.htmIts a tutorial on how to setup your email in Thunderbird
Also when setting up your email client for sending, it is important to check on these settings:
- the server requires PASSWORD AUTHENTICATION--the username is the full email address (ex. john@bigdomain.com), and the password is the one you assigned to the email account when you set it up in your HostPapa control panel
- the connection to the server is NOT over SSL (some email clients call this "secure connections")
- if port 25 does not work, try port 587 for the outgoing server; some internet service providers (such as Sympatico and Rogers in Canada) block port 25