This is a real nice service; it is merely a project to see how many people would use such a service. Basically, it works like this, you send your email to firstname.lastname@example.org and the folks at the other will rewrite by hand, put it in an envelope and send it off to the address provided by you. The best thing about this is that it is totally free service, which just goes to show just how many people are interested in snail mail after all!
According to the people behind the Snail mail my email project;
Dear all, thank you so much for your support. With over 1000 requests on July 19th alone, it is clear that there is a lot of love for snail mail. However, with such a huge response, comes a lot of pressure and a need to re-evaluate the structure of this project. This project will be going forward, but in a more focused capacity with an international network of volunteers! Please check back in the next day or two for more details.
Source [Incredible Things]