請教各位大大
最近同仁反應有某公司的信件收不到
今天做了一下smtpdiag的測試

從客戶端發送到我司郵件主機的信件是沒問題
但是客戶反應會收到退件訊息

如下
[<00>] XMail bounce: Rcpt=[judy@XXX.com.cn];Error=[The maximum number of delivery attempts has been reached]

[<01>] Error sending message [1331598748574.2950241184.3299.prot1] from [mail1.wdhac.com.cn].

ID: <12031300-0442-0000-0000-000000481D9F>
Mail From: <chen_juan@wdhac.com.cn>
Rcpt To: <judy@XXX.com.cn>

[<02>] The reason of the delivery failure was:

The maximum number of delivery attempts has been reached

[<05>] Here is listed the initial part of the message:

Received: from /spool/local
by mail1.wdhac.com.cn with prot1_XMail_ESMTP
for <judy@XXX.com.cn> from <chen_juan@wdhac.com.cn>;
Tue, 13 Mar 2012 08:32:28 +0800
Received: from mail1.wdhacoa.com ([172.19.5.1])
by mail1.wdhac.com.cn ([172.19.1.1]) with prot1_XMail_ESMTP;
Tue, 13 Mar 2012 08:32:25 +0800