Check your Airbnb Mailbox (Inbox)

Three times now, in the last 2 days, I sent a message to a guest, hit the send button and check to make sure that that the message was sent. It was. Only to come back a day later to see that the message disappeared and the guest never got it.
So check your Airbnb mailbox every now. I now copy and paste my messages in an email draft to make sure I can resend that message when the glitch happens.