My scenarios for mail server:

Mail Server <<<< Xeam <<<< Internet

Mail Server >>>> Xeam >>>> Internet

I want to change my server as mail offline. My server will Sent/Receive form Xeam.

+ IP Xeams: 192.168.1.2

+ Server mail: 192.168.1.1

+ DNS:

record MX: mail.abc.com

mail.abc.com >>>> 192.168.1.1

(Sent and receive from 192.168.1.1)

I can config relay to Xeams. But in-coming message not working. Anyone can help me ?

p/s: sorry about my english