Having been a very HAPPY myserver.org customer for some time now, I figured I'd try out your dynamic email product.
After 3 (THREE!!!) unanswered messages to
support@changeip.com and an unanswered voicemail on your 'technical support' dept mailbox, I finally figured the darn thing out, and my God, it works brilliantly!
Tell you the truth, the customer support nightmare aside, I couldn't be happier with your product. It just works, plain and simple.
BUT...
You must keep customer service as your primary objective if you want to stay afloat. I must say that after the myserver.org merger, customer service has gone south both on the myserver.org end and changeip.com end, and if it wasn't for Sam, who knows if you would ever answer any support questions (Maybe you could hire some USD freshmen to man the email boxes)...
If you can't keep up with the customer support, write up a quick how-to guide and post it.
So, my suggestion is to focus on the customer first, regardless of how great your product might be because there are many changeips and myserver.orgs just waiting to take your customers.
Good luck!