Server-side rules run on the server rather than in the Outlook client, so they let you apply rules before messages ever hit your system. Here’s how they work and what you can do with them.
When you set up normal rules in Outlook, they only work when the Outlook app is open on your system. These are called client-side rules because they work in the Outlook client app. They’re great for things like filtering email into different folders because the rules fire off when you open Outlook or when any messages hit your inbox.