Google is reporting service issues with Gmail, Google Documents, and Google Presentations. CCS has also noticed delays in the delivery of E-mail. The latest Google status information is here:
http://www.google.com/appsstatus
Please note that delays in delivering E-mail does not mean E-mail will be lost.
Note: Google has provided more information on the disruption which was resolved later the same day: http://gmailblog.blogspot.ca/2013/09/more-on-gmails-delivery-delays.html
-Computing and Communications Services