Super interesting idea. I had no idea that STEEM already had the capacity to send encrypted messages -- this is huge, in my opinion. I love the transparency that STEEM has to offer, but there's obviously still a place in the world for private discussions, and I'm glad this is available. I'm interested in checking out SteemChat a bit more as I get deeper into all this blockchain has to offer.

I think the idea of requiring a fee to send email (private or not) is very viable, and kinda-sorta reminiscent of old-school snail mail and stamps -- and the "return fee" option for non-spam emails is a great idea as well. Thanks for sharing this -- the future seems bright and the possibilities for STEEM seem to be more and more each day I read about it.