这种错误本地配置怎么改，3000why.com. config error: mail loops back to me (MX pro

lightwiter

前几天还可以收发信，今天一来发现不行了，这是root用户收到的错误邮件：
_________________________________________________________________
-----------------------------------------------------------------
Returned mail: see transcript for details

发件人：
Mail Delivery Subsystem <MAILER-DAEMON@localhost.localdomain>


收件人：
<root@localhost.localdomain>


日期：
今天 19:28:55


The original message was received at Mon, 30 Jun 2003 19:28:55 +0800
from sw31 [127.0.0.1]

   ----- The following addresses had permanent fatal errors -----
<lightwiter@3000why.com>
    (reason: 553 5.3.5 system config error)

   ----- Transcript of session follows -----
553 5.3.5 3000why.com. config error: mail loops back to me (MX problem?)
554 5.3.5 Local configuration error
550 5.1.1 postmaster... User unknown





封装的信件


loveyou

发件人：
root <root@localhost.localdomain>


收件人：
lightwiter@3000why.com


日期：
今天 19:28:36


this is a test mail.


封装信件结束


---------------------------------------------------------------------

这是我的配置文件
sendmail.mc
______________________________________________________________
divert(-1)
include(`/usr/share/sendmail-cf/m4/cf.m4')
VERSIONID(`linux setup for Red Hat Linux')dnl
OSTYPE(`linux')
define(`confDEF_USER_ID',``8:12'')dnl
undefine(`UUCP_RELAY')dnl
undefine(`BITNET_RELAY')dnl
dnl define(`confAUTO_REBUILD')dnl
define(`confTO_CONNECT', `1m')dnl
define(`confTRY_NULL_MX_LIST',true)dnl
define(`confDONT_PROBE_INTERFACES',true)dnl
define(`PROCMAIL_MAILER_PATH',`/usr/bin/procmail')dnl
define(`ALIAS_FILE', `/etc/aliases')dnl
dnl define(`STATUS_FILE', `/etc/mail/statistics')dnl
define(`UUCP_MAILER_MAX', `2000000')dnl
FEATURE(`no_default_msa',`dnl')dnl
FEATURE(`smrsh',`/usr/sbin/smrsh')dnl
FEATURE(`mailertable',`hash -o /etc/mail/mailertable.db')dnl
FEATURE(`virtusertable',`hash -o /etc/mail/virtusertable.db')dnl
FEATURE(redirect)dnl
FEATURE(always_add_domain)dnl
FEATURE(use_cw_file)dnl
FEATURE(local_procmail)dnl
FEATURE(`access_db',`hash -T<TMPF> -o /etc/mail/access.db')dnl
FEATURE(`blacklist_recipients')dnl
EXPOSED_USER(`root')dnl
FEATURE(`accept_unresolvable_domains')dnl
dnl FEATURE(`relay_based_on_MX')dnl
dnl FEATURE(promiscuous_relay)
MAILER(smtp)dnl
MAILER(procmail)dnl
__________________________________________________________________

relay-domains文件
3000why.com
___________________________________________________________________

local-host-names文件

www.3000why.com


实在是找不出原因了，还请各位老大指点迷津。