I think the Bmail project is not focusing on privacy as much as safety . Yes you can't be hacked on the blockchain but on the other hand your transactions won't be private. If you guys read the white paper there's no mention of the sender / receiver privacy. read "Various blockchains allow to distribute data on different chains that in combination with various types of enciphering allows to create the most flexible and protected communication network. We took
the best from this that there is for realization of bmail on the basis of technology a blockchain today. "