No, not really. There is something similar to what you describe. It is called bit essage.
Do you mean bitmessage?
bitmessage.orgBitmessage is a decentralized, encrypted, peer-to-peer, trustless communications protocol that can be used by one person to send encrypted messages to another person, or to multiple subscribers. Bitmessage encrypts each users' message inbox using public-key cryptography and replicates it inside its P2P network, mixing it with inboxes of other users in order to conceal user's identity, prevent eavesdropping and allow the network to operate in a decentralized manner. The Bitmessage communications protocol avoids sender-spoofing through authentication, and hides metadata from wiretapping systems.
This program does not work on top of the bitcoin blockchain.