Feature request: Allow setting different hostname to listen address (and server hostname)

[james-portman]

At the moment I have a server running in a cloud system behind NAT essentially.
I need to be able to have 0.0.0.0 as the listen address but a different hostname used for sending over in the SMTP banner etc

At the moment if I set the "correct" FQDN it then tries to listen on the public IP which doesn't exist on this server and fails

[waynew]

I'm pretty sure I'm doing this in my orouboros project, but I don't remember how. It would be good to document this, if it's possible

[james-portman]

(For now I am running it in a docker container with the hostname for the container set, then leaving it to listen on 0.0.0.0)

[pepoluan]

I think the problem is that the default Controller class does not pass hostname info to the SMTP class in factory()

I've implemented a pass-through mechanism in 7289e6d.