[net.mail.headers] Question about ARPA addresses

hoffman@pitt.UUCP (Bob Hoffman) (07/03/85)

For the last couple of months I have been getting Arpanet mail with
return addresses of the form:
	@SOMESITE.ARPA:USERFOO@SITEBAR.ARPA
	^^^^^^^^^^^^^^^
Regarding the "@SOMESITE.ARPA:" part of the address:
I must have missed the explanation of this somewhere along the line.
Is this designed to force replies to go to SOMESITE.ARPA first, using
USERFOO@SITEBAR.ARPA as the To: field entry?  Can someone point me
to the Arpa RFC that discusses this?

I need to modify my Sendmail configuration file to handle this, and
I want to do it right.  We don't connect directly to the Arpanet, but
we can send mail over CSNET, and we're one UUCP hop away from an Arpanet
site.

Many thanks,
-- 
Bob Hoffman, N3CVL       {allegra, bellcore, cadre, idis, psuvax1}!pitt!hoffman
Pitt Computer Science    hoffman%pitt@csnet-relay