Testing email on your local testing server will only work if you have an SMTP Server properly configured.
To be honest, I have never been successful setting up Mercury in Xampp, I do all me email testing on the remote server.
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.