Thank you for your continued feedback. As many people have pointed out, this is available on mobile today. Support for replying to a specific message is on the backlog for desktop. I’ll let you know when we have progress to share. Thanks.
An error occurred while saving the commentAnonymous commented
I figured out how to do this, but it's annoying.
Right-click > Copy ... the original message.
In the window where you compose your new message, type the > character. A "quote" box with a new background color appears. Paste in the original message. When you hit ENTER to add your own comments, you'll drop out of the quoted part so your message appears separately.
Other message threads on this Board show that the feature to more easily quote a previous message is in the works for Teams. Hopefully they can knock it out fast.