Adding a subject line to a message makes it a lot more scannable for everyone else. To do that, first you need to expand your compose box by clicking format icon. From there, just type the subject line you want in the first line of your expanded compose box.
An error occurred while saving the commentCorne commented
Still can't figure it out. I end up creating fake meetings with the correct subject and invitees. Then start a chat, and cancel the meeting.