Can't send or receive emails to outer world. only internal emails working

Hello
I have configures the server and able to receive emails between users of my domain. configured the A record and able to access it. I am unable to understand the documentation of the MX records. i request if any one can help me configure the MX records and other settings so that users will be able to send emails to gmail hotmail and other domains. My domain is registered with pananames<dot>com. thanks in advance.

Yes, Same problem. can’t send email out of the world , only intenal can work