[ale] Restricting smtp relaying to a list of addresses

[Newcombe at mordor.clayton.edu (Dan Newcombe)]

Is there a way with sendmail or smail that you can allow relaying from any
host only if the from address is found in a file?

Basically, make a file of all valid users whose e-mail addresses I want to
relay and point smail/sendmail to that file and say only relay these.

Yes...I know it is easy to forge the headers, but that is the lesser of
two evils.

	-Dan