example.com:
	# Indentation is optional, but improves legibility.
	# The following defines the user op@example.com;
	# <hash> is the hash of the password computed
	# with `smtpctl encrypt`
	user op <hash>
	# and define an arbitrary number of aliases
	alias service1
	alias other-alias

	user otheruser <hash>

	# aliases can be to virtual users on other hosts
	alias abuse	someone@example2.com

example2.com:
	user someone <hash>
	# …