When we work with customers, quite often they want to know, what is this server/client side stuff, all about?

When you use Outlook 2003 with Microsoft Exchange Server 2003, you can use both server-based and client-side rules. This small article talks about the differences, functions of server side rules vs. client side rules.

Server-based rules can be processed on the server.

For example, a user who uses the mailbox for the delivery location might have a rule that deletes all e-mail messages from a specific alias. Because both the Inbox and the Deleted Items folder are stored on the server, the rule can be processed there without interaction from the client.

Client-side rules require some processing by the client.

For example, a user has a personal folder (.pst) file where e-mail messages of certain types are stored. The .pst file uses a rule that moves all e-mail messages from a specific alias to that folder. In this case, the server cannot perform all the processing because the .pst file is located on the local computer and can be accessed only by Outlook 2003 and not by Exchange Server. Exchange Server 2003 creates a deferred action item on the server that runs the next time that files are synchronized. Because users must run deferred actions, client-side rules may have a very big effect on system performance, particularly when they work over slower connections.