I've validated that my email settings work using SMTP.
Validated using the Contact / Send Email as well as from the Joomla Global Configuration as well as the joomla K2 article print button.
Its just down to testing a sample newsletter mailing. At the bottom is a single email address to send to. I send to an email address for my site (internal to the hosting service) and it works. I try to any other external email address and it fails.
Error msg: Error in call to Mailing_send_test : mail() returned a failure. If I changed the email setting to SMTP, I get a long error, a 'failure to connect to , Invalid SMTP response code received.
Need Help :-(