add starttls

[MoritzFago]

[EtienneBruines]

I've started working on this, but I'm not sure if I'm capable enough to finish it.

RFC2595 is the one I'm trying to implement, but it's taking some refactoring (since it needs to modify the connection readers/writers).

[alienscience]

Please carry on if you would like. I am stuck on the getmessage command for at least another month.

Is this helpful:
https://github.com/flashmob/go-guerrilla/blob/master/goguerrilla.go#L367:L376

Its the TLS upgrade used by an SMTP server in go. It uses the go TLS library.

[EtienneBruines]

That is pretty much the implementation.

https://github.com/alienscience/imapsrv/blob/master/command.go#L59-L65

[EtienneBruines]

Turns out, using openssl s_client, it seems to work... However, browsers such as geary and thunderbird tend to break...

Somehow they do not respond after the OK message...

The problem

The client does not send a client-handshake during the handshake... The server keeps waiting for it, but the mail clients never send it ...

Solved

Nevermind ... this sub-issue is solved...

I guess it's quite important to send \r\n after the command ... My mistake.