For the last couple weeks I’ve been confused why Microsoft Outlook on my Mac would start consuming over 100% CPU while sitting idle, spinning up my fans, and generating a bunch of disk write activity.

At first I assumed it was because I am running the Fast Ring in order to run the new macOS design. However, the same build on my wife’s Mac, also running Catalina, never came anywhere near that even during what could be described only as “aggressive emailing.”

After messing around with adding and deleting accounts, hoping another beta update would fix it ... I finally got the idea to just drag Outlook to the Trash, and let Hazel detect this and offer to dump all of the associated files (cache, settings, etc) with it.

After I put Outlook back in Applications, and effectively set it up as new, everything is back to normal. 0.4% CPU

Outlook Overload