We are currently testing the new project room before rolling out countries for business management purposes.
Project Name: REU
What I noticed is, one of my colleagues was able to directly drag the mail and drop it to the attachment area and it worked, however for me it doesn't work.
In the below screenshot, you may see how she was able to attach the mail directly to the attachment area. (Screenshot1)
Also when I drag&drop mail to the comment area, it only appears as a subject with text (please check the screenshot2)

