hello i have search google on a simple tutorial on how to make a piping email.

first how does really email technically work?

"stmp is a process that binds to 25, waiting for email request that goes in from another stmp process(in another server) determined by the domain MX route that will send the message to port 25 if any email goes though the MX.domain.tld" that is in a nutshell how emailing work, am i right? or there is something wrong here?

second, so if im right, we need to set a SMTP server so we can receive incoming emails from MX SMTP route right? ive googled though google and found two best STMP servers from my opinion, they are EXIM and POSTFIX, can anybody give us a simple tutorial installing and setting up an email piping for a fresh installed linux/centos?

example

*.domain.tld -> allinonepipe.php

thanks.