Using older versions of Outlook for Mac for personal email and calendar
Hello James,
Thank you for your response.
If you are using the new outlook for mac, for now, this only supports server rules, and these need an exchange account. Ref: Create a rule in Outlook for Mac - Office Support (microsoft.com). If you are using another email account type like IMAP or POP, you can set up and use client rules in the legacy outlook.
Server rules vs. client rules in Outlook for Mac - Office Support (microsoft.com)
In case you have any further queries, please let me know.
Best Regards,
Ashraf.