Comment 3 for bug 21157

Yes, I can select all messages in a thread and dnd them to a folder, but the
functionality that's (apparently) missing is being able to grab a *collapsed*
thread and with one dnd move the entire thread to a folder. I've attached a
screenshot showing this functionality in Mozilla Thunderbird. You can see that
it offers a "balloon" icon for threads (circled in red). You simply dnd the
balloon icon, and the entire thread is dropped. I can't seem to achieve this
behavior in Evolution.