I have setup and tested the SMTP settings on my website. However, when I try to send a form from the website, I get  : "There is a problem with the configuration of your SMTP Server. Mail was not sent.". Mails are sent when I send from a "local"  mail account on the same server, but not any "outside" email addresses eg. Google or Yahoo.  Could this be an IIS or SMTP configuration issue on the server?