Using New Outlook on Windows for personal email, calendar, and contact management
Does anybody know how to quickly set a reminder for a received message in the NEW Outlook platform?
Sorry, No. This has been a "coming soon" for New Outlook since 2023. But it still ain't here yet.
https://learn.microsoft.com/en-us/answers/questions/4648916/email-reminder-and-follow-up-in-new-outlook-missin
As I'm sure you already know, best you can do in New Outlook is create a Task in "To Do" from the email and then put a Reminder on the Task. Certainly does not qualify as "quickly".
All I can suggest is that you Vote for and Comment on this Feature Request:
Bring back classic reminders
https://feedbackportal.microsoft.com/feedback/idea/84a52894-1f4a-f111-9a90-6045bdb3484a
(You must open the Feedback Portal link and "Sign In" at the top right of the Feedback page before you can vote).