Called Mail() without being connected with correct SMTP Server informations

I've recently installed e-Newsletter on my site, but I can not configure the SMTP settings. The PHP method is not working. I use the same SMTP settings on my iPhone and they work there. My hosting provider is NetworkSolutions.

The complete error message in the pop up when I click test connection is:
Failed to send test email! - Please check your outgoing email settings and server config to see if selected ports are open. Error details: The following From address failed: : Called Mail() without being connected

Is there a conflict with my provider or something? Would be great if I get help!

With reguards,
Fabian from Hack4Life