NDR 5.0.0 when sending mail with lots of attachment to 3 or more recipient   

Hi,

I will need to send some email with a lot of mail item attachments
(over 200 attached mails), when I send it to a few recipient (on the
same server), it will returned with a NDR 5.0.0 without specific
reason, ,while I sent to a single or 2 recipient, the mail can be
delivered.

I'm not sure if this is a known issue or if there is any work around,
any hints will be appreciated, thanks.

The server is running on Windows2000 Ent. SP4 with Exchange2000 SP3.

Below is the NDR message:

John Doe on 5/5/2008 10:49  AM
            The e-mail system was unable to deliver the message, but
did not report a specific reason.  Check the address and try again.
If it still fails, contact your system administrator.
            <email.com #5.0.0>


Regards,
Cody

date: Mon, 5 May 2008 20:12:31 -0700 (PDT)   author:   Cody Lo