sendmail relay
 

Is there a way to allow users on my system to relay without having to add all the domains to the relay-domains file?

are you talking about your network users or people outside your network?

The best way i know of this is to use pop authentication, where a successful pop session authenticates the user for smtp relay.

see http://rpmfind.net/linux/RPM/conecti...80cl.i386.html

i think there is another program called sasl that works with mail servers to do pop/imap authentication. i dont have a link tho but im sure if u look for sasl on the web u can find something.