Email reminder and follow up in New Outlook missing

I have been doing this "custom" date/time on Flag for Follow Up ...

If I understand correctly, you are Flagging an email in Outlook (which causes it to create a To Do "Flagged email") and then putting a Date and Time Reminder on the item in the To Do app. Is that right?

If you have already done all the Windows and Outlook settings to allow notifications and they are still not working, you are not alone. (Just Search for "new outlook notifications not showing").

The only additional things I can suggest:

1. Are the notifications in your "Action Center"?
   Click the Action Center icon in the notification area on the taskbar or use the keyboard shortcut Windows key + A.
2. Check your Windows "Focus Assist" settings. https://support.microsoft.com/en-us/windows/make-it-easier-to-focus-on-tasks-0d259fd9-e9d0-702c-c027-007f0e78eaf2
3. Check you To Do app setting.
   Click the "To Do" app icon in New Outlook.

Click the Settings Gear icon in the right panel of the To Do App (Just above "My Day".

Check the "Turn on reminder notifications" and "Connected Apps" -> Flagged email"

No idea sorry. I wish software companies would stop 'improving' programmes that work fine.

And, of course:

3. Just stick with Classic Outlook.

https://www.slipstick.com/outlook/classic-outlook-not-new-outlook/

https://www.slipstick.com/outlook/classic-outlook-2026/

https://support.intermedia.com/app/articles/detail/a_id/29771/~/identifying-and-switching-between-new-and-classic-outlook-interfaces

https://www.microsoft.com/en-us/microsoft-365/p/office-home-business-2024/cfq7ttc0pbm7
( Not for Mac. Only New Outlook for Mac. No Legacy )

https://learn.microsoft.com/en-us/microsoft-365-apps/outlook/get-started/licensing-options#frequently-asked-questions

( Not for Mac. Legacy End Of Support )