Gmail Timer - Schedule when to receive new mail by Musubi Google Apps Script | saves | Scoop.it
From blog.musubimail.com - October 27, 2012 9:40 AM

"Gmail Timer is a Google Apps Script which lets you take control of how often you’re interrupted by email. Timer will divert all of your incoming email into a folder until moving them all into your inbox on an interval you specify, whether once an hour, once a day, or anywhere in between." 


Via Martin Hawksey