hi, Exchange 2007 ver 8.1 (Build 240.6) mc@bbc.com.cn < this is a mail group of bbc.com.cn, which contain many user, such as simonlo@abc.com.hk, a@abc.com.hk.... etc when simonlo@abc.com.hk send mail to this mail group then abc.com.hk will auto gen a error message to him, the mail can send to the other user successfully How do i change setting to stop this message? the message : From: Mail Delivery Subsystem [mailto:Mailer-Daemon@abc.com.hk] Sent: Tuesday, June 15, 2010 11:26 AM To: Simon Lo Subject: Delivery Status Notification (Failure Notice) Hi. This is an automatically generated Delivery Status Notification at [abc.com.hk] I'm afraid I wasn't able to deliver your message to the following recipient: simonlo@abc.com.hk This is a permanent error, I've given up. Sorry it didn't work out. The error that the other server returned was: 551 User not local; please try ---- Attachment is a copy of the message.

Hi Simonlch, Do you mean. simonlo@abc.com.hk send an email to DG which contains siomonlo@abc.com.hk, and the email could send to others successfully except for the siomonlo@abc.com.hk Could you make a test send a emal direct to simonlo@abc.com.hk. Is ther tihird party installed on your server, or some special rule? You also could check the tracking log to post more information about it, we could do more research regarding to your issue. Regards! gavin