[Wlug] I could not read from my my qmail server.

Hi all, Can you please help me.... I've got a problem with qmail, I've built my qmail server, Here, I can send an email using my email address, cleary listed on the recepient name that the sender's address is listed. But, these following things happen : 1. I can connect to my server, the connection and autorization are workin' nice, It alwais say "NO NEW MESSAGES" 2. When I'm tryin' to send an email address to the one of the email address that defined on my mail server, it always MAILER_DAEMON replied with the subject is "FAILURE NOTICE" So, can somebody tell me what has happened here... ? What Shoul I Do ? Thanks All, Bye there and have a nice day! Note : I'm using qmail with pop3.