Starting this Friday, March 29th, our email service started sending duplicate emails to some users (and none to others).  We apologize to those of you that received duplicate emails or none at all.  As of 2:15PM US West Coast time we have turned off our email service (lesson and comment announcements).  We will turn it back on once we have isolated and fixed the issue.

Mike

Our email system is now fixed.  If anyone receives duplicate emails in the future, please let me know.  Thanks.