Hello everyone and thank you for taking the time to request this feature. As part of our investigation on adding this capability, we ask that you please help us gather additional information on how you use Pin. This helps us to prioritize and design the feature to be exactly what you need to get more done!
Please use the below link to access a short survey about Pin:Laurel commented
We use shared email boxes that we need to pin important emails to the top of the inbox for quick reference. We know that the pin feature is available in Web Mail but for business needs, we have all been instructed to start using all the shared mail inboxes in Outlook. We no longer have the ability to keep the important emails pinned at the top. This would be very useful to those of us who know it is available in Webmail but not in Outlook.