Rewriting Exchange addresses
"The company you work for buys a smaller company. The newly acquired company exists in its own Active Directory forest and has its own Exchange organization. Management wants all e-mails coming from the newly acquired company to reflect the parent company's domain name. There are techniques that can be used to consolidate the networks, but doing so takes a lot of time and requires an extensive amount of planning. You need a plan for changing e-mail addresses now." More...