Microsoft, its partners, and its competitors have been making much ado about “the cloud.” For many organizations, moving messaging and collaboration services to the cloud is a sound business move. However, the cloud isn't for everyone. Depending on the degree of control you require over your information, and the services used to access it, you may be better off maintaining your own self–hosted services. The HP E5000 series of hardware helps you economically deploy Microsoft Exchange at your own facilities while still giving you the option to usealongside your own services. This paper describes the use cases where you can deploy the E5000 series to provide high-quality messaging services at an affordable cost.