how to use postfix send receive email

[Jianping Zhu <jzhu fisher forestry uga edu>]

I have redhat linux 7.2 download postfix rpm and install it, but when i 
try to use pine to send email (for regular user jzhu. email addree 
jzhu mydomain com) I does not work, how can i set up postfix as a 
regular email server to send and receive emails for all users?

Thanks