I feel it would be extremely useful if the facility to have all incoming emails marked as "Flagged" was available, either as a general setting or by setting up a rule to enable this to happen - it would be useful for people who work through hundreds of emails a day and need to mark them as completed but save having to mark every single one with a flag initially

DATES: DAY/MONTH/YEAR
SEARCH RESULTS 'TOP' AND 'ALL'..
WHY NOT JUST ALL FROM MORE RECENT?

Can you please sync categories from the Outlook desktop application to the Office365 and Mobile versions of outlook? This would compete with Gmail's label function and boost efficiency

Please make NO SOUND the default

Planner hub is hanging up my browser and not accepting any changes.

Send to calendar straight from email message when a specific calendar invite has not been sent.
i.e. "... the event will be Wednesday, Sept. 9th at noon PST..."

Allow for spell checking in multiple languages, recently this option was changed with the introduction of Microsoft Editor, which only allows for one language at a time and needs to be set (deep) in the Outlook settings.
Before you could use the spell checker form the web browser (Edge allows for multiple languages to be checked), but this does not work anymore.

It would be convenient if we could customize the default MailTips message for per function.

Set the additional buffer such as travel time in addition to the actual meeting duration when scheduling meeting rooms.
“End meeting early” is the similar function but it cannot add the buffer time. So, it would be great if we could add the travel time.

New "Editor" features are worse than just annoying. They're sloppy and get in my way

Personalized dictionary! I'm so tired of my name being highlighted as misspelled when I have always been able to teach the dictionary to learn the spelling.

i want to save a mail to my onedrive... i am not talking about attachments, but the mail.

When I delete an e-mail, sometimes it deletes two e-mails. Why is that?

It would be convenient if an admin can set the default work time option in Outlook for multiple users at once in case of multiple user creation in his organization. This would be helpful to set company work time for all employees from the start.

The Earlier fashion of Synced email was a good fashion. Please restore that Functionality.

If I don't complete a task that I created to do today it should still show in the side calendar as due

In Outlook on the Web for Office 365; When I open another person's mailbox and click on Notes, I see my notes instead of theirs.

Folder/inbox goes to top after closing a message. Please revert to old feature of keeping place in folder upon closing message.

Problem. Outlook includes my signature in a reply even though I switched off the reply with signature setting.