Why don’t email clients have panic buttons? My mailer takes about five seconds to send a short text message to my mail-server, but it takes about five seconds to bring up the progress-dialog and click the cancel-button. How many times have you hit the “Send” button and then thought, “oops, I shouldn’t have done that?” Un-sending is a pipe-dream, but why don’t more mailers have a “cancel all pending sends and move to drafts” button?