It would be nice to auto-save messages when writing them in Inbox. It happened to me a couple of times to write a lengthy reply to a student or a class and when I pressed send, I got an error message and I had to re-write everything. Auto save or at least on the event of an error to keep the message it would be great. Also I think that Shift+Enter key combination when writing should not send the message and just move to the next line.