***** Change sendto & aliasdbm to know about quoted commas.
	Currently, quoted commas delimit aliases when they should be
	ignored.

   ****	Collect mail together that can be sent all at once, i.e.,
	create equivalence classes of hosts.  This could end up needing
	great knowledge about network topology, but most errors would
	end up being inefficient although still ok.

    *** Put host aliasing into the users file, e.g.,
	``vax135!:research!vax135!''   This would simplify
	configuration considerably, but it might not be worth it.
	For example, this is too sensitive to be in a file that
	is writable by all users.

     ** Collect all names that are local in advance, and send
	them all off to /bin/mail at once -- fork before sending so
	that we can return status quickly.

     ** Handle :Include: specifications.

      * (Somehow) have "From" person modified so that if an alias exists
	for the person, it will appear post-aliased rather than pre-aliased,
	especially (perhaps only?) in ARPANET mail.  For example, if there
	exists an alias "fabry->cory:fabry", then if mail comes in from
	"cory:fabry", make it appear as though it were from "fabry".
	This should probably be in Mail (put "From" and "Date" lines in)
	or in the arpa mailer.

      * Do aliasing on mail being returned also (?).