最近几我们服务器向我们服务器的用户发送邮件时，时常会有以下信息退回。 以前一直都是正常的。

不过我的域名是都香港hknet.com那边申请的。请大家帮分析一下原因。

The original message was received at Mon, 13 Jun 2005 16:51:28 +0800
from [211.96.7.131]

----- The following addresses had permanent fatal errors -----

(reason: 500 error)

----- Transcript of session follows -----
553 5.3.5 mail.mydomain.com. config error: mail loops back to me (MX problem?)
... while talking to opal.hknet.com.:
>>> RCPT To:
<<< 500 error
554 5.0.0 Service unavailable
451 4.4.1 reply: read error from opal.hknet.com.
... Deferred: Connection reset by opal.hknet.com.
,... Deferred: Connection reset by opal.hknet.com



Reporting-MTA: dns; localhost.localdomain
Received-From-MTA: DNS; [211.96.7.131]
Arrival-Date: Mon, 13 Jun 2005 16:51:28 +0800

Final-Recipient: RFC822; l-so@mydomail.com
Action: failed
Status: 5.5.2
Remote-MTA: DNS; opal.hknet.com
Diagnostic-Code: SMTP; 500 error
Last-Attempt-Date: Mon, 13 Jun 2005 16:51:34 +0800

现在电信的线路去香港总存在很多问题，你考虑问问电信那边。