I know I said I was going to shelve the Groovy Email Server. Instead, I kept working on it. I will probably keep at it until I get it to a semi-finished state. Right now it is in a semi-semi-finished state.
Right now I have implemented most of RFC 1939 (POP3) and RFC 5231 (SMTP). (I do not plan on implementing RFC 3501 (IMAP).) I can send email from another account to my GES, and I can retrieve them locally using Alpine. So far I would call it pretty successful.
I have not tried to retrieve messages with attachments. I have not looked at RFC 5232 (Internet Message Format), which may cause problems down the line. I have not tried to send messages while logged into Alpine.
I have written this using PostGres. I have the tests actually writing to the database. I know a lot of test purists will object, but I saw an article linked from Hacker News: Don’t test with SQLite when you use Postgres in Production. One of the comments was a quote (supposedly from NASA): Test what you fly, fly what you test. Maybe it’s not the absolutely best way to test and develop, but as Voltaire wrote: Do not let the perfect be the enemy of the good.
I have to update the README on github. I think I will try to get it to a point where I can also send from Alpine. I might go further than that, and try to get it to the point where I can replace my Apache James server. We shall see.