It doesnt happen right away, normally takes an hour or so for it to start hogging them all, but once it happens Outlook becomes unusable and I have to Force Quit everything.

In Activity Monitor its showing CPU usage at somewhere like 780, which is just absolutely bonkers.

Would really appreciate any advice or tips you could throw my way.

To uninstall, I moved all Office programs to the Trash, emptied it, then navigated to LibraryContainers and then deleted all of the pertinent com.microsoft folders, as well as all Microsoft folders located in LibraryGroup Containers (UBF8T346.

Then I reinstalled from my Office 365 login page, and have yet to reproduce the issue.

All settings will be saved along with the local copy of the mailbox.

There really should be no issues at all just running the full upgrade.

When Outlook database is several GBs on size it gives all kinds of troubles; check the database directory size.

For months before this update, everything would run smoothly.

I would leave Outlook open all day while working and have no issues at all.

Ever since 15.22, after about an hour of running it suddenly and drastically starts using more and more of my CPU, and then internal fan of the MacBook sounds like a jet engine.

High CPU usage, fan runs all the time that I have Outlook 15.22 open.

Was not occurring before upgrading.

Have not yet uninstalledreinstalled but will post the results when I do.

I have tried changing the IMAP sync settings to 20 minutes from 2 minutes and turned off the IMAP IDLE feature on each account and it APPEARS that Outlook is no longer eating up CPU.

So frustrated with Outlook and yet there are clearly some features I needwant.

As you can see it blew away a bunch of.plist files (saved them in.tmp just in case I regret this later) as shown below for info.

In my case, something was wrong with the domain binding and I was unable to change my password.

Once IT has readded my Mac to the domain, the problem ceased to exist.

Outlook For Mac 2016 Running Slow