Email preview no longer remains highlighted while clicking on said email

Question

Email preview no longer remains highlighted while clicking on said email

Liam Ramus 5

Hello,

Up until recently, when I select an email preview it highlights in blue, then I select the email itself it turns grey to show that it is selected but inactive. The following screenshot is from my personal computer: Image A.jpg

Now when I do the same action the email preview has no highlight at all anymore and turns white blending in with the other emails in the list. The following screenshot is from my work computer: Image B.png

Its hard to explain but this really messes with my work flow and slows me down.

I've tried uninstalling and reinstalling Outlook. I've even completely cleared the cache and deleted all previous app settings using Office-Reset (a 3rd party tool) with no luck. I've tried restarting my computer as well thinking maybe it was an OS bug. Next may be updating my OS so hopefully it overrites whatever weird OS level cache file is the culprit.

M5 Macbook Pro 14 inch
macOS Tahoe 26.2
Microsoft Outlook for Mac Version 16.109.3 (26053122)
Legacy Outlook

Any ideas on how to fix this?

Rayyan Fawad 1,075 Reputation points

2026-06-04T21:16:10.35+00:00

Hi Liam, this annoying highlight glitch is almost certainly tied to a macOS accent color mismatch or a rendering bug specific to the Legacy Outlook interface on macOS Tahoe. Since you have already completely wiped the app settings and reinstalled Outlook, the issue isn't the app's internal cache, but rather how the legacy UI framework pulls the system-wide selection color when a list item loses focus. Before waiting on an entire OS update, try going into your Mac's System Settings > Appearance, and change your Accent color and Highlight color from multicolor to a specific fixed color (like Blue or Graphite). If that doesn't force Outlook to redraw the background selection gray, your best bet to restore your workflow immediately is toggling off Legacy Outlook in the top menu to switch over to the New Outlook interface, which uses a completely different modern rendering engine that doesn't suffer from this focus-blending bug.
Hornblower409 14,930 Reputation points

2026-06-06T03:19:12.8366667+00:00

@Liam Ramus said

Microsoft Outlook for Mac Version 16.109.3, Legacy Outlook

I don't think that Legacy Outlook for Mac is available for any version since 16.102
https://support.microsoft.com/en-us/office/end-of-support-for-legacy-outlook-for-mac-7b9cf644-7035-4345-a151-8c1c7a65ac25

from my personal computer ... from my work computer

Personal

Work

1 -- Are both computers running the same version of Outlook for Mac (16.109.3) and the same MacOS (e.g. Tahoe 26.5.1)
Rayyan Fawad 1,075 Reputation points

2026-06-06T04:22:54.3333333+00:00

Great spot on the version cutoff, Hornblower409—that is a massive piece of the puzzle. If both machines are indeed sitting on build 16.109.3, they are well past the point where the native "Legacy Outlook" switch can be natively toggled back.

Liam, since the software builds match, the hidden discrepancy between your personal and work layouts is likely a staggered server-side feature rollout or an enterprise configuration profile managing your work machine. To force your personal machine's interface into exact alignment with your work setup, your best bet is to sign out of your personal account, add your work profile to the personal Mac first to let its configuration policy pull down the correct UI layout elements, and then add your personal inbox back as a secondary account!
Liam Ramus 5 Reputation points

2026-06-08T13:42:48.26+00:00

My personal Mac is running Outlook 16.89.1 and Sonoma 16.5.
My work Mac is running Outlook 16.109.3 and Tahoe 26.2.

I forgot to mention that I previously tried to switch to the New Outlook and that did work but my company uses shared calendars that for whatever reason do not work in the New Outlook. I also already tried the accent color thing and that wasn't the issue.

I'm not sure what you mean by "Legacy Outlook" is not available as I am currently using Legacy on 16.109.3 as previously stated. Also note that the error is with my work computer so I don't know why I would want to add my work computer's configuration to my personal computer. My personal computer is working as it should.
Liam Ramus 5 Reputation points

2026-06-08T13:46:30.64+00:00

Additionally a similar issue is with the sidebar but instead of it being gray when selected and inactive, it has thin lines on the top and bottom. Screenshot 2026-06-08 at 9.45.00 AM.png
Liam Ramus 5 Reputation points

2026-06-08T16:26:10.7733333+00:00

UPDATE: I asked my pal at work who is on the same everything as me now (he's on Tahoe 26.3 now actually) and he said he updated to Outlook 16.109.3 and the issue is occurring now but it was not occurring before the update.

My guess is its something between this new outlook update and Tahoe that is causing it.
Hornblower409 14,930 Reputation points

2026-06-08T17:54:13.83+00:00

@Liam Ramus said

updated to Outlook 16.109.3 and the issue is occurring now but it was not occurring before the update

Thanks for the update. There is not really anything I can suggest except:

Roll back to Outlook for Mac 16.109.2 (May 26, 2026). Please advise if you want to try this.

Or submit a Problem Report (to be sure Microsoft knows about it) and wait until Microsoft (hopefully) fixes it in the next Release.

https://support.microsoft.com/en-us/office/contact-support-within-outlook-for-mac-d0410177-8e65-4487-93f7-206a3a3d71a8
Liam Ramus 5 Reputation points

2026-06-08T18:33:34.2266667+00:00

Thanks! how do I rollback to that version?
Hornblower409 14,930 Reputation points

2026-06-08T21:19:11.7733333+00:00
@Liam Ramus said

how do I rollback to [Outlook for Mac 16.109.2 (May 26, 2026)]

I would suggest that you:

Submit a new Question on this forum with the specific request "How to rollback Outlook for Mac from 16.109.3 to 16.109.2", to ensure that you get the latest instructions from a knowledgeable source.

Or bring in Microsoft Support to do it for you.
https://support.microsoft.com/en-us/office/contact-support-within-outlook-for-mac-d0410177-8e65-4487-93f7-206a3a3d71a8

If you want to try it yourself:

See https://learn.microsoft.com/en-au/answers/questions/5736043/how-to-rollback-to-previous-version-of-outlook-mac

Office for Mac Outlook Update Packages
https://learn.microsoft.com/en-us/officeupdates/update-history-office-for-mac

Stop Auto Updates
https://learn.microsoft.com/en-us/answers/questions/5818924/kill-microsoft-autoupdate

Open any Office app

Help > Check for Updates

Uncheck “Automatically keep Microsoft Apps up to date”

Your answer

Rayyan Fawad 1,075 Reputation points

2026-06-04T21:16:10.35+00:00

Hi Liam, this annoying highlight glitch is almost certainly tied to a macOS accent color mismatch or a rendering bug specific to the Legacy Outlook interface on macOS Tahoe. Since you have already completely wiped the app settings and reinstalled Outlook, the issue isn't the app's internal cache, but rather how the legacy UI framework pulls the system-wide selection color when a list item loses focus. Before waiting on an entire OS update, try going into your Mac's System Settings > Appearance, and change your Accent color and Highlight color from multicolor to a specific fixed color (like Blue or Graphite). If that doesn't force Outlook to redraw the background selection gray, your best bet to restore your workflow immediately is toggling off Legacy Outlook in the top menu to switch over to the New Outlook interface, which uses a completely different modern rendering engine that doesn't suffer from this focus-blending bug.
Hornblower409 14,930 Reputation points

2026-06-06T03:19:12.8366667+00:00

@Liam Ramus said

Microsoft Outlook for Mac Version 16.109.3, Legacy Outlook

I don't think that Legacy Outlook for Mac is available for any version since 16.102
https://support.microsoft.com/en-us/office/end-of-support-for-legacy-outlook-for-mac-7b9cf644-7035-4345-a151-8c1c7a65ac25

from my personal computer ... from my work computer

Personal

Work

1 -- Are both computers running the same version of Outlook for Mac (16.109.3) and the same MacOS (e.g. Tahoe 26.5.1)
Rayyan Fawad 1,075 Reputation points

2026-06-06T04:22:54.3333333+00:00

Great spot on the version cutoff, Hornblower409—that is a massive piece of the puzzle. If both machines are indeed sitting on build 16.109.3, they are well past the point where the native "Legacy Outlook" switch can be natively toggled back.

Liam, since the software builds match, the hidden discrepancy between your personal and work layouts is likely a staggered server-side feature rollout or an enterprise configuration profile managing your work machine. To force your personal machine's interface into exact alignment with your work setup, your best bet is to sign out of your personal account, add your work profile to the personal Mac first to let its configuration policy pull down the correct UI layout elements, and then add your personal inbox back as a secondary account!
Liam Ramus 5 Reputation points

2026-06-08T13:42:48.26+00:00

My personal Mac is running Outlook 16.89.1 and Sonoma 16.5.
My work Mac is running Outlook 16.109.3 and Tahoe 26.2.

I forgot to mention that I previously tried to switch to the New Outlook and that did work but my company uses shared calendars that for whatever reason do not work in the New Outlook. I also already tried the accent color thing and that wasn't the issue.

I'm not sure what you mean by "Legacy Outlook" is not available as I am currently using Legacy on 16.109.3 as previously stated. Also note that the error is with my work computer so I don't know why I would want to add my work computer's configuration to my personal computer. My personal computer is working as it should.
Liam Ramus 5 Reputation points

2026-06-08T13:46:30.64+00:00

Additionally a similar issue is with the sidebar but instead of it being gray when selected and inactive, it has thin lines on the top and bottom. Screenshot 2026-06-08 at 9.45.00 AM.png
Liam Ramus 5 Reputation points

2026-06-08T16:26:10.7733333+00:00

UPDATE: I asked my pal at work who is on the same everything as me now (he's on Tahoe 26.3 now actually) and he said he updated to Outlook 16.109.3 and the issue is occurring now but it was not occurring before the update.

My guess is its something between this new outlook update and Tahoe that is causing it.
Hornblower409 14,930 Reputation points

2026-06-08T17:54:13.83+00:00

@Liam Ramus said

updated to Outlook 16.109.3 and the issue is occurring now but it was not occurring before the update

Thanks for the update. There is not really anything I can suggest except:

Roll back to Outlook for Mac 16.109.2 (May 26, 2026). Please advise if you want to try this.

Or submit a Problem Report (to be sure Microsoft knows about it) and wait until Microsoft (hopefully) fixes it in the next Release.

https://support.microsoft.com/en-us/office/contact-support-within-outlook-for-mac-d0410177-8e65-4487-93f7-206a3a3d71a8
Liam Ramus 5 Reputation points

2026-06-08T18:33:34.2266667+00:00

Thanks! how do I rollback to that version?
Hornblower409 14,930 Reputation points

2026-06-08T21:19:11.7733333+00:00

@Liam Ramus said

how do I rollback to [Outlook for Mac 16.109.2 (May 26, 2026)]

I would suggest that you:

Submit a new Question on this forum with the specific request "How to rollback Outlook for Mac from 16.109.3 to 16.109.2", to ensure that you get the latest instructions from a knowledgeable source.

Or bring in Microsoft Support to do it for you.
https://support.microsoft.com/en-us/office/contact-support-within-outlook-for-mac-d0410177-8e65-4487-93f7-206a3a3d71a8

If you want to try it yourself:

See https://learn.microsoft.com/en-au/answers/questions/5736043/how-to-rollback-to-previous-version-of-outlook-mac

Office for Mac Outlook Update Packages
https://learn.microsoft.com/en-us/officeupdates/update-history-office-for-mac

Stop Auto Updates
https://learn.microsoft.com/en-us/answers/questions/5818924/kill-microsoft-autoupdate

Open any Office app

Help > Check for Updates

Uncheck “Automatically keep Microsoft Apps up to date”