Somebody please help!
I need to restrict SMTP relaying on a postfix mail server. Normally setting it to trust the local subnet works, but, in this case, my client uses NAT, and so EVERYTHING looks like it is coming from the local network. How do I specify that a user must be a local user and that they must authenticate with the server before they are allowed to send. We have been blacklisted, and I need to set this up before we get unblacklisted