한메일로만 메일이 안갑니다.

안녕하세요?

솔라리스 9를 쓰는 서버로 sendmail을 사용해서 이메일을 사용하고있습니다.

다른곳은 상관없는데 유독 한메일로만 메일이 안보내지네요

스팸서버로 등록되있는것도 아닌데 말이죠

반송메세지는

----- Original Message -----
From: "Mail Delivery Subsystem" <MAILER-DAEMON>
To: <ahn@jina.re.kr>
Sent: Tuesday, November 01, 2005 4:24 AM
Subject: Returned mail: see transcript for details

> The original message was received at Mon, 31 Oct 2005 23:25:59 +0900 (KST)
> from [211.117.124.149]
>
>   ----- The following addresses had permanent fatal errors -----
> <minsvati@hanmail.net>
>    (reason: 551 5.7.1 Relaying denied)

   ----- Transcript of session follows -----
> ... while talking to mx8.hanmail.net.:
>>>> RCPT To:<minsvati@hanmail.net>
> <<< 551 5.7.1 Relaying denied
> 550 5.1.1 <minsvati@hanmail.net>... User unknown
>

입니다. 답변좀 부탁드려요. 고수님들!!