XADM: Cannot Restrict Mailbox Administration by Server

MORE INFORMATION

An Exchange Server system uniquely identifies every object, which includes every user, in the Exchange Server directory with a Distinguished Name (DN). The DN is in the following format: The DN identifies a unique path in the Exchange Server directory tree to locate a user. Administrative permissions also flow down the structure of the DN, which reflects the structure of the directory tree.

Notice that a user's DN includes the user's organization, site, and Recipients containers, but not the user's home server.

The home server is merely an attribute of a user, in the way that a user's department or phone number is an attribute of that user. You can no more assign administrative access based on different home servers than you can based on different phone numbers.

It is very easy to move users from one server to another server in a site because the home server is treated as an attribute of the user.

NOTE: The Server Recipients object that is displayed in the Exchange Server Administrator program under each server is not an actual container, but a "virtual container" that is displayed for administrative convenience. Because it is not an actual directory object, it has no directory properties or associated permissions.

To approximate management of users on a server-by-server basis, use one of the following two methods, but be aware that both methods greatly limit your flexibility if you need to move users:

• Create custom recipients containers for each server in the site, and create all of the users on a given server in the appropriate container. Grant each administrator View Only Administrator permissions for the Site object and Administrator permissions only for the appropriate Recipients container.
  
  This method restricts your freedom to move users between servers and containers without breaking the container-based administrative model. You can still move a mailbox to another server, but if you do, you disconnect the mailbox from the appropriate administrative permissions, unless you change the container at the same time.
  
  To move a user to a different container, you must actually delete and re-create the user. You can preserve user data in a personal folder file (.pst) during this process, but replies from the user to outstanding messages from other Exchange Server users are non-deliverable, because the user's DN changes. Replies to messages from foreign mail systems remain deliverable in most cases, because foreign e-mail proxy addresses need not change. -or-
  
  
• Isolate each server or administrative group in its own site. In most cases, this results in an organization that is composed of many sites that each contain a single server.
  
  The Exchange Server administrative model defines the fundamental unit of administration as the site, not the server. This method of managing users on a server-by-server basis conforms with the design and intent of Exchange Server administration, and this makes it more secure and simpler to implement than the first method. It is also less likely that security will be inadvertently breached because permissions were mistakenly granted. The following are the major drawbacks of this method:
  • You cannot move users unless you delete and re-create accounts. The current version of Exchange Server (Exchange Server 5.5) does not support the movement of users between sites, because when users move between sites the user's Distinguished Name must be changed.
  • You must manually configure messaging connectivity and directory replication between each site. In a site, these functions are automatic.