My guess is that it is probably 1). Somebody in their anti-spam team read "Google Calendar", saw my display and thought "Nah, that's no google calendar" :D Bu

My guess is that it is probably 1). Somebody in their anti-spam team read "Google Calendar", saw my display and thought "Nah, that's no google calendar" :D But maybe it was something else. It's of course possible I violated some kind of policy. But they're not sending me any debug messages :D