Ask HN: Gmail Bouncing Google Calendar?

Quite simply, I have Google Calendar set to send me e-mail notifications, and some of them are being outright bounced by Gmail, which then, ironically, has Google's Mailer-Daemon e-mail me about the bounced message, giving me a notification of sorts.

Any idea what the heck is going on with Google?

Do you have the bounce message?

It could have been your mailbox was unavailable (full? Overloaded by someone repeatedly refreshing the webmail page?). When a mailbox is unavailable, even briefly, you'll start to get mailer Daemon messages.