Got Ethereum; Try ETHMail!
ETHMail to make e-mail Great Again With Blockchain!
ETHMail is an email provider. It providers email services like Gmail. The twist is that you don't register an account with ETHMail, you just use your Ethereum wallet (pub/prv key pair) signature ability to prove that you are in control over given mail account.
Deep down it's IMAP and SMTP server designed in such a way to allow direct communication between Ethereum addresses using standard email technology.
No setup is needed. Plain old email to slightly weirder email address. The receving person doesn't need to use ETHMail yet. Your email will wait for them on ethmail.cc and it will appear in their inbox when they first check their mail.
Yes! ethmail.cc works exactly like your standard email provider.