Since the Inbox version was launched, I cannot send messages anymore. I am instructor of many courses, maybe because of this, it takes so much time to load messages (when it loads!). When I click new message and fill "To:" I have to wait about 5 minutes to appear the list of classes. Then finally when I write the message and click "Send", many often the message is not sent and no error message appears. It is a very important educational tool that now is useless for me, I have to use the Announcements instead, in each class.