Please allow us to hide/unhide the sen to OneNote and other Add-ins buttons so that the ribbon would not be re-arranged because of the space that is taken up by the add-ins icons.

Include calendar for public holidays

How many times do you receive (long) e-mails that you keep in your inbox because you want to return to them later, e.g. to check one of the links that was included? Problem is, anytime you do go back to this message, you have to read everything again because you don't remember anymore WHAT it is you wanted to check later. Here's where siple inking would come in handily. Let the user mark the section of the e-mail (s)he want to check later.

sometimes we have a lot of emails as conversational emails (forward/reply) I wish if we have a way "keep the last email" -FOR REFERENCE instead of deleting each email in email thread manually.

Please add holidays to calendars. Not able to add international holidays.

Support handling of custom protocols:

1. Treat custom protocol links as hyperlinks: protocol://my-awesome-link (need ability to click and highlight it)
2. Support open application that is responsible for handling custom protocol links:
With example above application responsible for protocol:// handling should be opened

We have an office of over 100 employees often sending images between design teams. Our previous email client application had the ability to resize images to lower resolution at the time of sending an email. Without this feature in Outlook we have found more difficulty in our workflow.

I love the idea of the dark mode option, however on most cases I find it hard to read with a dark background due to recent updates. I hopes there's a permanent option to switch to light mode for reading pane, instead of having to push the light switch all the time when scrolling through emails.
Now I gotta turn off the whole dark mode option for reading and efficiency purposes.

Put the categories back in the sidebar! Why on earth would you take that feature away? Now I can't view contacts or calendar by category, rendering the categories essentially useless.

Be able to see and insert file types like JPEG, PNG, PDF and other non Microsoft document files located in cloud in either OneDrive or Sharepoint to be able to add it in the “Insert Link” feature when creating or responding to messages.

Voting button is available for Outlook running on other systems than Mac. Please add the voting button function to Outlook for Mac .

Allow the ability to customize and set a BCC email address by default, instead of having to enter an email address in the BCC field every time.

Currently, you can only set to BCC yourself as default.

at the moment, all days and events look exactly the same, regardless if that day/even has passed. By dimming any past days and events, the most relevant and pressing events will be highlighted and easy to recognize.

Please Implement the option to open or syncronize online calenders. And let us import public holidays

Corporate mail server is CalDave - whether we like it or not. Want to integrate in Outlook rather than using iCal!

pin calendar and contacts and tasks on the side like in the windows outlook version

There should be an option to disable the notifications (reminders) for shared calendars events in Outlook for Mac.

I suggest you add spell check before sending as an option. Yes there is spell check as you go but spell before sending is better and what people are used to using outlook. Not sure why the MAC version has to miss such clear essentials.