센드메일로 메일을 보내는데 리턴되는 메일은.. 도와주셈

우여곡절끝에 센드메일을 설정하고 메일을 한번 발송해보았는데여... 근데..

>N  1 root@selab.superserv  Thu Feb  7 15:20  14/411   "test"

이건 제가 보낸 메일인데 그 담 2번째 꺼는 도무지 무엇을 말하는건지..

뭐가 잘못된 것이죠?? ㅠ.ㅜ 고수님들의 많은 가르침부탁합니다.

>N  1 root@selab.superserv  Thu Feb  7 15:20  14/411   "test"
 N  2 MAILER-DAEMON@selab.  Thu Feb  7 15:20  62/2000  "Returned mail: see transcript for details"
& 2
Message 2:
From root  Thu Feb  7 15:20:10 2002
Date: Thu, 7 Feb 2002 15:20:10 +0900
From: Mail Delivery Subsystem <MAILER-DAEMON@selab.superserver>
To: root@selab.superserver
MIME-Version: 1.0
Content-Type: multipart/report; report-type=delivery-status;
        boundary="g176KAV02093.1013062810/selab.superserver"
Subject: Returned mail: see transcript for details
Auto-Submitted: auto-generated (failure)

This is a MIME-encapsulated message

--g176KAV02093.1013062810/selab.superserver

The original message was received at Thu, 7 Feb 2002 15:20:10 +0900
from root@localhost

   ----- The following addresses had permanent fatal errors -----
ninanada@hanmail.net
    (reason: 501 5.1.8 Sender domain must exist(selab.superserver))

   ----- Transcript of session follows -----
... while talking to mx3.hanmail.net.:
>>> MAIL From:<root@selab.superserver> SIZE=68
<<< 501 5.1.8 Sender domain must exist(selab.superserver)
501 5.6.0 ninanada@hanmail.net... Data format error

--g176KAV02093.1013062810/selab.superserver
Content-Type: message/delivery-status

Reporting-MTA: dns; selab.superserver
Arrival-Date: Thu, 7 Feb 2002 15:20:10 +0900

Final-Recipient: RFC822; ninanada@hanmail.net
Action: failed
Status: 5.1.8
Diagnostic-Code: SMTP; 501 5.1.8 Sender domain must exist(selab.superserver)
Last-Attempt-Date: Thu, 7 Feb 2002 15:20:10 +0900

--g176KAV02093.1013062810/selab.superserver
Content-Type: message/rfc822

Return-Path: <root>
Received: (from root@localhost)
        by selab.superserver (8.10.1/8.10.1) id g176KAW02091;
        Thu, 7 Feb 2002 15:20:10 +0900