I just tested your form and it went through fine.
I could only get it to fail by not adding a correct email address or leaving one of the other fields blank.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.