"receiving" involves mail being delivered on your server, eg.  from other mail servers on the internet, as well as your mail client connecting to the pop/imap server and downloading messages - which piece isn't working?  Eg.  if you send email from gmail or somewhere, what happens, it bounces or it seems to work buy you don't receive it when checking? ( check your mail.log to see what happens there) When your mail client (pop or imap) tries to check mail, do you get any errors?  If you send a message to yourself so that it never leaves your server, are you able to receive that? 

"receiving" involves mail being delivered on your server, eg.  from other mail servers on the internet, as well as your mail client connecting to the pop/imap server and downloading messages - which piece isn't working?  Eg.  if you send email from gmail or somewhere, what happens, it bounces or it seems to work buy you don't receive it when checking? ( check your mail.log to see what happens there) When your mail client (pop or imap) tries to check mail, do you get any errors?  If you send a message to yourself so that it never leaves your server, are you able to receive that? 

Click to expand...

i can do sending mail to other server (yahoo,googe,etc) but when im tries replying that messages, i got a reply, "undelivered mail returned to sender"
and this my mail.log

in the postfix, myhostname should be mail.creativauz.com i think....
WHich guide did you follow? 
If you run a multi server setup, hostname should be full fqdn , web.example.com, db.exampble.com. 
If its single server, it sould be web.example.com or panel.example.com