e4900的一个mail问题。

summerblue

这个是telent后mail信息


bash-2.05# mail
From MAILER-DAEMON Tue Nov 14 08:57:10 2006
Date: Tue, 14 Nov 2006 08:57:10 +0800 (CST)
From: Mail Delivery Subsystem <MAILER-DAEMON@system2>
Message-Id: <200611140057.kAE0vAIQ021098@system2.>
To: root@system2
Subject: Returned mail: see transcript for details
Content-Length: 1356

This is a MIME-encapsulated message

--kAE0vAIQ021098.1163465830/system2.

The original message was received at Tue, 14 Nov 2006 08:57:10 +0800 (CST)
from root@localhost

   ----- The following addresses had permanent fatal errors -----
/
    (reason: 550 5.7.1 </@system2>... Cannot mail directly to files)
    (expanded from: /)

   ----- Transcript of session follows -----
... while talking to [127.0.0.1]:
>>> DATA
<<< 550 5.7.1 </@system2>... Cannot mail directly to files
550 5.1.1 /... User unknown
<<< 503 5.0.0 Need RCPT (recipient)

--kAE0vAIQ021098.1163465830/system2.
Content-Type: message/delivery-status

Reporting-MTA: dns; system2.
Arrival-Date: Tue, 14 Nov 2006 08:57:10 +0800 (CST)

Final-Recipient: RFC822; /@system2.
X-Actual-Recipient: RFC822; /@system2
Action: failed
Status: 5.7.1
Remote-MTA: DNS; [127.0.0.1]
Diagnostic-Code: SMTP; 550 5.7.1 </@system2>... Cannot mail directly to files
Last-Attempt-Date: Tue, 14 Nov 2006 08:57:10 +0800 (CST)

--kAE0vAIQ021098.1163465830/system2.
Content-Type: message/rfc822

Return-Path: <root>
Received: (from root@localhost)
        by system2. (8.12.10+Sun/8.12.10/Submit) id kAE0vAIP021098
        for /; Tue, 14 Nov 2006 08:57:10 +0800 (CST)
Date: Tue, 14 Nov 2006 08:57:10 +0800 (CST)
From: Super-User <root>
Message-Id: <200611140057.kAE0vAIP021098@system2.>


--kAE0vAIQ021098.1163465830/system2.--

summerblue

我想知道的是这个长久的致命的错误的具体解释
知道的大拿帮帮忙吧。