Hi, I have an Exchange Server 5.5 with service pack 4 at WindowsNTS 4.0 SP6a. I have to change the current domain. In this scenario, the mail ID's for all the mailboxes will also be changed from abc@xxxxxxxxxxxxx to abc@xxxxxxxxxxxxxx Also the IP address of the machine running Exchange server will be changed as I AM CHANGING THE ISP. Will there be any problems for me? Has anyone done it before? Please reply!