I just signed up here the other day and this flashing envelope thing won't stop flashing. There are no messages in my inbox. I even sent myself a test message, then selected "check all" then selected "delete selected". The test message disappeared and the inbox is empty, but even after a page refresh, dumping the browser history/cache/website data, signing out and back in, the "blinking envelope" icon keeps blinking.
I see some others have had this problem. Your help would be appreciated.