You will need your recipients to also decrypt it themselves, then. And handle your own key-exchanging. Not trivial, if you want to be able to email lots of people.
Bitmessage is a beautiful concept but I've read many people having concerns over several aspects of how secure it really is. I hope the entire web one day works on a similar model.
Bitcoin is one such thing. Well, not the bitcoin protocol directly, but the basic idea of a block chain can be used for many interesting things, such as decentralised encrypted communication.
This is notoriously known for not encrypting metadata, though, which is impossible because this very metadata is used to make email actually work.