We are still using exchange 2003 mail server in our organization, and no planning to upgrade to exchange 2007 or 2010 in the future. We have been used outlook 2003 to communicate with exchange 2003 for a long while. it is very easy to configure as long as active directory been created a valid user name and mail box. We had used AT&T internet service and DNS hosting in the past, everything is working good. Recently we switch to Verizon internet service, but they do not have a service to host client DNS, so we have to use our domain registration agent, network solution, as our new DNS hosting, our corporate email and website are working fine. But recently we upgrade our user outlook 2003 to outlook 2007. and then we have a big problem to connect our exchange server 2003, I understand outlook 2007 is using autodiscover to seach email connection. We can not connect our staffs email with outlook 2007 now. see attachment. Is this cause by our DNS hosting, network solution? or something we can easily fix in our end. Thank you so much,Paul from project hospitality.