Outlook forwarding rules when outlook is not running

Do the email forwarding rules on outlook work if the outlook itself isn't running? Are the rules server-side or client-side by default, if I'm using Exchange Server?

Your rules are hosted on the Exchange server, so naturally you can't access them while in offline mode in Outlook.

If you are an admin or have access to Exchange server ,your Exchange mailbox can receive it with the server-side rules which will run even when you're offline , but if you are using Outlook to create rules, messages/rules are only applied if you go online.

FYI for the server side filtering : Link

I note that on my version of Outlook, I can setup SOME rules to work offline. For example, moving an email to a folder, or forwarding it. But if I add a "mark as read" action, I get a popup:

"(!) This rule will only run when you check your email in Outlook. If Outlook isn't running, this rule won't work for email you check online or from another device"

The rule is then marked as "client only".

So to answer the OP's question: "it depends"