From ncr-sd!hp-sdd!ucsdhub!sdcsvax!ucsd!brian Tue Mar  8 12:49:07 PST 1988

Here's what we do with mail on our campus mail gateway machine
"ucsd.edu":

First, we turn the To: (and Cc:, etc) addresses into a canonical form to
simplify further processing.  Specifically:

	user@host	->	user@host.ucsd.edu
	host!user	->	user@host.uux
	user@host.uucp	->	user@host.uucp
	user@host.any	->	user@host.any

Next, we do the following for special cases:

	1. Is it a domain we can handle locally via uucp?  i.e.,
		user@*.cts.com	->	crash!*.cts.com!user
	2. Is it an on-campus host (in any of three lists)?
		user@campushost.ucsd.edu
		user@campushost.uux
			is resolved to the appropriate mailer
	(This means that campushost!user is properly handled)

	3. Is it a pseudo-domain (i.e., for some attached network)?
	If so, we forward it to the appropriate gateway.

		user@host.bitnet	sent to the bitnet gateway
		user@host.span		sent to the span gateway
	
	4. Is it a uucp host that we talk to DIRECTLY?  If so,
	just give it to uux to send on its merry way.

	5. Is it a uucp host that we don't talk to directly? If
	so, give it to the routing version of uux to figure out
	some path based on the maps and send it on its way.

	6. Is it an on-machine address?  If so, deliver locally.

	7. It must be an Internet address.  Resolve with MX and the
	nameserver.

This is all done with sendmail; we use 'uumail' to supply the routing
version of uux but that's AFTER we resolve to the uucp mailer based on
the style of the hostname.  The bug with this is that if someone right
down the road from us and a good uucp connection starts using
domain-style return addresses, we'll wind up sending mail to them
through their Internet mail forwarder until I get around to putting
another special-case rule in there to catch them.

I probably forgot something we do; this seems too simple.

Curious (and BRAVE) folk can view this wonderous sendmail.cf file in the
public FTP directory on host UCSD.EDU.  It mostly works; I make no claim
to it being entirely bug-free.  There is no such thing as bug-free
software anyway.

	Brian Kantor	UCSD Postmaster & Chief News Weenie
		UCSD Office of Academic Computing
		Academic Network Operations Group  
		UCSD B-028, La Jolla, CA 92093 USA
		brian@ucsd.edu	BRIAN@UCSD ucsd!brian