- Go to File > Manage Rules & Alerts.
- Click "New Rule" under the Email Rules tab.
- Select "Apply rule on messages I receive" and click Next.
- Choose any conditions you want (or none to apply to all emails).
- In actions, check "forward it to people or public group".
- Select the forwarding email address and finish the rule.
Note: Outlook desktop rules only run when Outlook is open, unless configured on the server side (Exchange).