Running Outlook on the iMac causes the screen to flicker and eventually black out and reduce to half/split screen display.

This is definitely still happening to me with Outlook on iMac. Has nothing to do with Skype in my case. 

It's been a problem ever since Microsoft introduced "Dark Mode" "improvements" - has completely messed with my computer. Whatever you did to hook into dark mode is broken. Here's my specs:

iMac (Retina 5K, 27-inch, Late 2015)

Graphics:  AMD Radeon R9 M395 2048 MB

Seems like every new update you introduce to Outlook takes away functionality. I can't move email between gmail accounts anymore. I don't see sent/deleted/spam in unified folders anymore. Your product decisions are taking away functionality more than adding to them. Now this dark mode fiasco. 

Please make the product better not worse. Please purchase an iMac with these specs, see what you did to break the app, and then fix it. 

All other email clients for Mac are terrible. Outlook was great until you started making it worse with each update. Please please please stop taking away the best parts and introducing bugs.

Dear AussieFlem,

I had exactly the same symptoms as you described, I thought it manifested like a hardware problem, but wasn't convinced... ran all types of diagnostics, no errors found...

(almost same configuration iMac as you)

I even upgraded my disk, from fusion to SSD, and added more memory...

The only difference I found was the Flashing was "faster" after the upgrade ???

Stopped using outlook and problem has not reoccurred in 2 months. Issue was directly attributed to Outlook, was happening 3-5 times per day whilst viewing emails in outlook.

I prefer using outlook, and still paying for it, but can only use it on iPad.

Will periodically check back to see if it goes away, but not holding my breath.

Hopefully the problem will disappear as quickly as it appeared. (lol)

Regards

Mal

Hi all,

I seem to have found a "work-around" that works for me, albeit not an optimal one. I have a second screen attached to my iMac and I've noticed that if I keep Outlook on that screen all the time I don't get these glitches anymore. My second screen is non-retina by the way, not sure if that is somehow related.

Also having the same problem, having similar hardware: 

Mac (Retina 5K, 27-inch, Late 2015)

AMD Radeon R9 M395 2 GB

I run Outlook 16.25 (Office 365), Teams (corporate communication) and Skype (personal). Having the same issues for about 2 weeks (some 4-5 times a day).

Hi All,

If you experience a similar issue in your iMac, please try to create a new thread in our forum since the root cause may be different in your case. We'd love to collect more detailed information and do the further investigation for you. 

And I've consulted with our engineering team, they've been aware of this issue. From their proposal, it's recommended for you to feedback in Outlook for Mac UserVoice website to share with them directly. It's highly appreciated for your understanding.

Regards,

Marvin