Google Inbox “happy” hour

Delivery to the following recipient failed permanently:

     inbox@google.com

Technical details of permanent failure: Google tried to deliver your message, but it was rejected by the server for the recipient domain google.com by aspmx.l.google.com. [2a00:1450:4010:c08::1b].

The error that the other server returned was: 550-5.2.1 The user you are trying to contact is receiving mail at a rate that 550-5.2.1 prevents additional messages from being delivered. For more 550-5.2.1 information, please visit 550 5.2.1 http://support.google.com/mail/bin/answer.py?answer=6592 j9si8791583lab.13 - gsmtp