How to write simple mail server in java?

Question

I want to write a mail server, but I don't know how. Would you please give me some direction where to search for exmaples?

Answer 1

Essential reading for implementors of SMTP servers:

• RFC 821 (and updates, most recent is RFC 5321)
• RFC 822 (and updates, most recent is RFC 5322)

The Wikipedia article Simple Mail Transfer Protocol has a huge amount of additional information and links.