For all the Google employees who read this blog, this very serious GMail problem... GMail has stopped sending outgoing mail to its destination.
As an email administrator who has access to log files on our server, I can confirm that email from GMail never reaches us. There are lots of people experiencing this problem as it has been happening since yesterday afternoon.
Here is a thread that you should read: GMail Problem Solving Group.
Update (Oct.12, 3:02PM)
It looks like everything is back to normal... thanks G!