Here are a few fundamentally different async protocols in development which could challenge SMTP: DIME - https://en.wikipedia.org/wiki/Dark_Mail_Alliance https

Here are a few fundamentally different async protocols in development which could challenge SMTP: DIME - https://en.wikipedia.org/wiki/Dark_Mail_Alliance https://en.wikipedia.org/wiki/Dark_Mail_Alliance Math Mesh - https://mathmesh.com https://mathmesh.com TMTP - https://mnmnotmail.org https://mnmnotmail.org (my work)