Per-install email configuration

Hey!

I'm looking for some way of changing email configuration per install (eg. different mail server).

It should work a bit like the config/database.yml which I keep per install (eg. it isn't part of the repository) and then just be included in the config/environment.rb

Is this a sensible way to go about it and if it is, how can should I implement it?

Is there some other, more clever way of doing it?

Regards, Mikkel