Most likely you forgot to upload the template page your email is based off. It may not automatically upload with the required files, make sure to upload the entire webassist/ directory and see if that fixes it.
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.