enhancement to UNIX mail program

[utzoo!decvax!ucbvax!hpvax!sri-unix!Dpk at BRL]

	At BRL, we are running the MMDF mail system, but the changes
I made would be applicable to other systems at least in theory...

	MMDF is set up with various channels (out to UUCPnet, out
to the ARPANET, local delivery, BRLNET, etc.).  For each channel
there is a list of hosts that can be reached on that channel.
The channel programs hide the workings of the different networks
they connect to.  For instance, the ArpaNet is a flat network, whereas
UUCP is a store and forward.  We wanted to remove the need for users
to have to know the UUCP paths to a given host so I built a mapping table
from hostname to a!b!c!hostname.  The UUCP channel program looks up
hostname and finds the appropriate path and poof!

	About the only problem this has is the maintainence issue.
the mapping table should be kept up to date (although not necessary
as you can still specify long paths).  Another potential problem is
making sure all hosts have unique site-ids.  This is currently
not a problem but there is no assurance that it wont become a problem
in the future.  Perhaps some coordination in this area would be useful.

	Has anyone thought about some more elegant means for handling
a randomly organized store and forward network?  For instance, by
specifying each host by its neighbors.  How then do you choose a path?

				Cheers,
					Doug

PS.  I would be interest in talking with others working on network
     mail issues at Santa Monica.