501錯誤的可能原因及mdaemon中設定對此的影響

zhengfeng2100

各位，以下是我公司一位客戶發mail過來的紀錄，提示501錯誤，好象是域名和IP不一致。<br>
想請教大家兩個問題：<br>
1，造成501錯誤的所有可能原因<br>
2，mdaemon中的哪些設定會對此錯誤的報告造成影響<br>
<br>
強烈要求斑竹幫忙解釋一下，謝謝!<br>
<br>
Wed 2004-11-03 13:11:49: Session 7270; child 1; thread 912<br>
Wed 2004-11-03 13:11:45: Accepting SMTP connection from [62.20.88.194 : 3253]<br>
Wed 2004-11-03 13:11:45: Looking up PTR record for 62.20.88.194 (194.88.20.62.IN-ADDR.ARPA)<br>
Wed 2004-11-03 13:11:45: D=194.88.20.62.IN-ADDR.ARPA TTL=(1241) PTR=[mx1.delaval.com]<br>
Wed 2004-11-03 13:11:45: Gathering A-records for PTR hosts<br>
Wed 2004-11-03 13:11:45: D=mx1.delaval.com TTL=(59) A=[62.20.88.194]<br>
Wed 2004-11-03 13:11:45: --> 220 senyun.cn ESMTP MDaemon 7.0.1; Wed, 03 Nov 2004 13:11:45 +0800<br>
Wed 2004-11-03 13:11:49: <-- EHLO setusrv013.delaval.com<br>
Wed 2004-11-03 13:11:49: Performing lookup on setusrv013.delaval.com (looking for 62.20.88.194)<br>
Wed 2004-11-03 13:11:49: Name server reports domain name unknown.<br>
Wed 2004-11-03 13:11:49: --> 501 <setusrv013.delaval.com> is invalid or DNS says does not exist<br>
Wed 2004-11-03 13:11:49: SMTP session abnormally terminated (Bytes in/out: 29/136)<img src="../leadbbsfile/UBBicon/em04.GIF" width=20 height=20 align=absmiddle border=0>