Early this morning, shortly after midnight Pacific time, the email notification system started spooling email to the send queue without delivering the email. It has affected numerous customers, but not all. We have been working throughout the day to determine the problem and will update this notice as we work toward a solution. We apologize for this delayed email delivery and are working with our providers to get it resolved ASAP.
Update 2017-08-21 6:15 PM Pacific time: We resolved the issues by removing SendGrid as the relay provider for email. Email is now being sent as it was before the recent change was made to use SendGrid. We will be re-evaluating SMTP provider options for long-term improvements, but for now we have returned to the previous method of sending directly from our data center servers.