I want to thank you a lot for your reply.
That is a very good HowTo and I am/was following that logic described for a few day now. I know this is not working for me probably because of my authinfo file (that I gave another name to).
Let's just see if I can explain my case here so that you can provide your useful help to me (if you don't mind)...so, the mail relay is an exchange server in which I must authenticate with a user from the domain.
So, my domain user is crnogue, the pw is MyPW the domain is telecom.es, the relay name is email@example.com
(W2k3) and I am trying to send mail from a machine called firstname.lastname@example.org
So I put these entries in the auth file:
AuthInfo:email@example.com "U:firstname.lastname@example.org" "I:email@example.com" "P:MyPW"
AuthInfo: "U:firstname.lastname@example.org" "I:email@example.com" "P:MyPW"
I created a user in my RHEL named crnogue so that the exchange server recognize the user name and I tried to email with that user. Still not working. What am I doing wrong?