So is it right to say that though I want only a small handful of users from certain domains/organizations to send email to me, it could be email gateways (or "mail relay servers" ??) that are unrelated to those domains/organizations that make Tcp25 connection to my email server?
As for the external POP3 clients that connects to my POP3 server (which runs in the same box as postfix), it makes sense to permit on my firewall for those POP3 clients to connect? Thanks U
