In Outlook for Windows I can add a send delay to every message as a rule. I like doing this because it gives me an extra minute or more to change my mind about an email after clicking 'Send'.

The web version offers a 10-second delay, which is even better than nothing.

Like Spark Mail, or Canary Mail, the ability to color code email accounts. Would appear color coded in left nav bar and also with an indicator in email list.

Why? Makes it real easy to see what account an email came in to.

Allow Embedded Outlook Messages (.msg files) to be opened in Outlook for Mac. Colleagues regularly forward embedded emails that I can't open

The "Send Availablity" feature is iOS is one of the most useful features I've ever used. I actually switch away from a desktop interface to the mobile version of Outlook just to use that feature. It is that great! It would be AWESOME if the Outlook for Mac team could bring that feature to the Mac Desktop client.

Encouragement... 🤛🏼

Not able to sort by Flag - clicking on column does not work, menu option is not there

Add support for voting buttons.

There's no way to access the Address Book with people on your server anymore.

So far hasn't done anything useful to my search results, and is just extra clutter

Just like on outlook.com it would be nice to be able to pin messages at the top of folders and sync whatever message you pin in outlook.com to also pin it on the app.

Currently, there seems to be a lot of 'dead' space in the new UI. While I like the more modern look, it should be possible to makt certain UI elements a bit more compact, much like is possible on Outlook for Windows...

I suggest that you open all events, meetings bookings in edit (less clicks) mode when you x2 click it

Copy paste from calendar items like in Outlook for Windows would be great to have as well in Outlook for Mac.

Right now all sub-folders including sent items show up by default making it very long list for each email.

It will be very useful to integrate a button that, while replying to a mail, send a message and archive all the thread.

Ability to add columns such as Message Size. My organisation has strict quotas so its handy to be able to delete large messages

Conversation threading should be a per-folder setting, so, for example, my Inbox could have it on and my Sent Mail could have it off.

use cache exchange mode to download mails to an OST file.
Currently user are downloading everything.

The ability to customise or use other keyboard shortcut schemes (e.g. Gmail) on the web app makes it 2x faster to process email. Please bring it to the desktop app!