I have Postfix installed. I am doing some simple tests. I am trying to send an email from my account on a box from within my LAN. I am doing like this:
# mail firstname.lastname@example.org
Subject: Test Test
I then hit enter. Right after I do this, I receive an email in my inbox that says:
I'm sorry to have to inform you that your message could not be
be delivered to one or more recipients. It's attached below.
How do I fix postfix where it can send email to outbound receivers outside of my LAN? It works inter-box when I send it say root to username.