I strongly recommend looking into Chasquid: https://github.com/albertito/chasquid https://github.com/albertito/chasquid Only SMTP though, for the IMAP part you

I strongly recommend looking into Chasquid: https://github.com/albertito/chasquid https://github.com/albertito/chasquid Only SMTP though, for the IMAP part you need to use something else like Dovecot.