Outlook 2016 CPU usage running continuously at around 100%

Question

I recently purchased a Office 365 Business plan, and have installed the desktop Office 2016 apps. I am experiencing continuous high CPU utilization, causing the fan in my MacBook to run much of the time. Activity Monitor shows that Outlook is the culprit.

I have Outlook 15.11.2 and OS X 10.10.  I have one Exchange 2010 (SP2) accounts and two IMAP accounts. All are showing folders up to date, and mail is being sent & received normally.

I haven't noticed any issues with the other Office 2016 applications.

I have already tried creating a new identity and setting up accounts again from there (rather than importing from OUtlook 2011 which I did at first installation), but it did not help.

I have also installed the suite on my iMac, and experience the same issue there, so it is not specific to my laptop.

There is an earlier thread on this issue, started in 2014 and with posts up to mid July this year, with not a single response from MSFT. It is clear there is a bug here, as it stands I am going to have to abandon Outlook 2016 and revert to 2011, so if it can't be fixed I'd like a refund.

Answer 1

I tried every option listed in this thread - to no avail.

What worked for me was to turn off Dictation:  (System Preferences\Accessibility\Dictation) 

As soon as I did that, the CPU use returned to normal instantly.

Answer 2

I don't think this a bug. Have come across users having the same issue and restarting the system has actually fixed it. So, you can try that first. Also you may have pending updates to be installed for office. So check and install the updates to see if that helps too.

Answer 3

I am not sure what the correct definition of 'bug' is, but the software is being used in a supported configuration and is failing to work correctly for a number of people (see thread Outlook 2016 preview - outlook high CPU on Macbook Air for example). It seems to have been present in the preview and through many/all versions up to 15.11.2 which was current at the time I posted. I have tried many of the apparent fixes in that thread (deleting Exchange account and recreating it, creating entire new identity, reinstalling), so far without lasting success.

I suspect it may affect even more users who don't realise it's happening. Only because the fan on my MacBook was running too much did I notice it. My iMac was not overheating and I only discovered it was doing the same thing when I specifically looked at Activity Monitor.

I see that 15.12.3 is now released. I will try installing that, and throw in a reboot for good measure but as you can imagine I am not very hopeful!

Answer 4

I can confirm that updated to version 15.12.3 did not fix the issue.

Nor did a reboot. I also tried removing the exchange account from my profile, restarting and adding it back again.

The high CPU usage persists.

Answer 5

Still no fix for this issue, and very frustrating that I have paid for a product that I cannot use and there appears to be no way of getting tech support, other than paying $500 for an incident. (If anyone knows another way to contact MSFT please let me know.)

I am forced now to either abandon Outlook 2016 and use either web access or roll back to Outlook 2011.