Snail Mail was the first envelope printing application for Mac OS X, integrating with the OS' bundled Address Book application in a number of ways, and was quite popular for a number of years. It was discontinued due to me having no time to maintain it any more, due to having kids and trying to run this web site, amongst other projects.
This is probably not of much interest to people here, but I'm excited and had to tell somebody.

In particular, I wanted the project to continue for the sake of the many users who depended on it (I'm aware of users in large companies such as a commercial airline manufacturer, and even a well known desktop operating system producer). It would be a shame if they could not continue to have the support they want and for their application to continue to evolve and improve.