Originally I was trying to keep the .env file with as few superfluous options as possible, but I can see this possibly being useful for something like testing via GMail. Then again, the MailCatcher stuff is very good, so maybe YAGNI?

If you think you might use this more generic version of the config, I'd be fine with doing it the way you suggested. If not, maybe we can refactor towards it later if and when the need arises.