Exchange NDR 5.2.1的问题，谁有遇到过？一台Exchange 2003 ABC.com 不能发送到 ABC.com.cn
两个域一个在中国一个在美国。
但ABC.com能发送到123.com
abc.com.cn 跟123.com是一台服务器，所以不是网络问题。
退信消息如下：
Your message did not reach some or all of the intended recipients.
Subject: Test message sent at 2:41 AM
Sent: 6/30/2008 2:42 AM
The following recipient(s) cannot be reached:
Undeliverable Incoming Email on 6/30/2008 2:42 AM
The message reached the recipient's e-mail system, but delivery was refused. Attempt to resend the message. If it still fails, contact your system administrator.
<ABC.com #5.2.1>
在网上google了一下
5.2.1
Message was too big.
Check the permissions as well as the message size.
但确实不是邮件大小的问题。
谁有这方面的经验？