Description of the illustration ''%s''arch_2tier

This figure represents a two-tiered Messaging Server architecture. In this figure, Messaging Server customers connect to Messaging Server's front-end components through a public network access layer, while the back-end components of Messaging Server are found within a private data layer network. Each front-end Messaging Server component includes load balancers to spread the components across multiple servers. In the figure, the front-end components include: MMPs, MTAs, Webmail Servers and the Delegated Administrator. The back-end components include: Message Stores, Contacts and DNS Servers, and LDAP Directories. Each Messaging Server component is spread onto multiple machines in order for Messaging Server to continue to expand, if needed.