Hi friends, One of our new client is interacting for 1st time with us, when he send the email to us he received below NDR. This is an automatically generated Delivery Status Notification. Unable to deliver message to the following recipients, because the message was forwarded more than the maximum allowed times. This could indicate a mail loop.

I would start with message tracking logs on the clients side and check the internet message header of that NDR and see where the problem may lie.

Which server is generating NDR, is it your server or your customer server. It will isolate issue whether looping occure at your place or his place. Anil

our server.......

OK, Its looking looping issue because of maximum number of host between sender and receiver SMTP server. The max hop count property is set for each virtual server, and you can manually override this setting (the default setting is 15 for Exchange 2000 Server and 30 for Exchange Server 2003). Additionally, look for any situations that could cause loops between servers. Increase hop count in SMTP virtual server and then test it. if issue does not fix by increasing hop count then you can create one new SMTP connector for this new domain and then test it. How to configure the SMTP connector in Exchange 200x: http://support.microsoft.com/kb/265293Anil

You still need to look at the NDR headers to get the complete picture.

Hi Exchange server 2003, Any update for your issue? Any more information regarding to your issue? Regards! GavinPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.