Can anybody give me some incite on how to make this work. I have an exchange server that answers/sends mail for mydomain.com where addresses are in the format user@xxxxxxxxxxxxxxxxx I wish to add a new mail server (iis smtp) specifically as a lsoft listserver where that machine sends/answers mail in the format user@xxxxxxxxxxxxxxxxxx How do I make it so that @list.mydomain.com addressed mail never goes to the exchange server and vice-versa. Thanks in advance Confidentiality Notice Unless expressly stated otherwise, this message is confidential and may be privileged. It is intended for the addressee(s) only. Access to this e-mail by anyone else is unauthorized. If you are not an addressee, any disclosure or copying of the contents of this e-mail or any action taken (or not taken) in reliance on it is unauthorized and may be unlawful. If you are not an addressee, please inform the sender immediately and delete this message from your system.