The added code would not cause problems.
If it sends to one, it should send to both. I'd check spam settings and spam folders to be sure that it isn't sending and you just aren't seeing it received properly.
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.