Copy and paste attachments
Copying an attachment from one email and pasting it in another email or copying a local file and pasting it as an attachment in an email is standard functionality in Outlook for Windows. This is currently missing in Outlook for Mac. This makes it quite hard when you want to use an attachment in a new email. The only way is to drag and drop which is not practical when you have several windows open.
This is a very important feature that I constantly utilize in the Windows version! Please add to the Mac version.