I would recommend checking out wildduck https://wildduck.email https://wildduck.email, It is backward compatible, smtp, imap, pop3 and support unicode email as

I would recommend checking out wildduck https://wildduck.email https://wildduck.email, It is backward compatible, smtp, imap, pop3 and support unicode email as well, and it is REST API callable. So you can receive and send email.