求助 請幫小弟看看此錯誤訊息

[j826907]

小弟公司有一客戶使用maild架設郵件伺服器
目前客戶有反應寄信到@innovexinc.com的郵件都會被退
客戶端域名:yfa.com.tw

因小弟初步檢測客戶端的dns設定並無大問題，煩請各位幫忙看看
附上2份客戶給的退件訊息，麻煩各位大大幫小弟看看是哪邊的問題，謝謝
敬祝大家新年快樂

The original message was received at Fri, 29 Dec 2006 14:17:36 +0800 (CST)
from mail.yfa.com.tw [220.134.111.28]

----- The following addresses had permanent fatal errors -----
<LLo>

----- Transcript of session follows -----
... while talking to cluster6.us.messagelabs.com.:
>>> DATA
<<< 553-Message filtered. Please see the FAQs section on spam
<<< 553-at http://www.messagelabs.com/support/ for more
<<< 553 information. (#5.7.1)
554 <LLo>... Service unavailable



The original message was received at Fri, 29 Dec 2006 14:17:33 +0800 (CST)
from mail.yfa.com.tw [220.134.111.28]

----- The following addresses had permanent fatal errors -----
<SLai>

----- Transcript of session follows -----
... while talking to cluster6.us.messagelabs.com.:
>>> DATA
<<< 553-Message filtered. Please see the FAQs section on spam
<<< 553-at http://www.messagelabs.com/support/ for more
<<< 553 information. (#5.7.1)
554 <SLai>... Service unavailable

[ingolf]

[j826907]

謝謝您的幫忙