Testing from your local computer will not work unless you have an SMTP Server installed to relay the email.
You should do your testing on the live server.
In many cases, leaving the SMTP Server and Port settings blank will be ok, but if it is still not working, you will need to contact the host to determine the correct SMTP server and port settings to use.
Your host may have an SMTP Server that requires authentication, if this is the case, you will need to use the Pear Mail For SMTP mail object instead of the standard mail object.
The from address should be a valid email address for your domain, make sure to use a different address for both the from address and the to address.