Hi Charles! reBoxed was actually more of an experiment in how quickly I could build something - I just had the idea for it last Friday. It's not going to be reMail's main product. :-)
Especially since it is not true: I'm a very fast coder too and some product I sold or that is working well today started like one/two days of hacking where an alpha was already working.
The point is that this is just the start. Even if you don't add new features after the first two days you need weeks or months more to make this product rock solid, with a good UI, seriously scalable, documented, easy to use for the newcomer, and so on.
To get started fast is an invaluable thing, it helps building a lot of things in your life so you simply trow away what appears useless, not working as expected and so on. But to do great things a lot of work is needed anyway.