postfix configuration
 

Okie, I'm just finish configure my postfix. My postfix is MTA for my MUA Squirrelmail. I'm using Linux RedHat 9.0 OS.

Somehow I'm only able to send mail but not able to receive mail.

Plus I recognize when I send mail to a mailbox to such as Bellsouth.net or yahoo.com.. I see the header of the email state as user@localhost.mydomain.com. I want to change it to such as :

user@mydomain.com, and how do i do that?

And what configuration that I need to implement in the main.cf file for my MUA Squirrelmail to be able to receive mail from the outside source? Because at the moment I only can send mail.

Please help, and I thank You.