At approximately 9 a.m. EST on February 2, 2015, our third-party hosting provider suffered a partial service disruption affecting their DNS infrastructure. As a result, some of our customers experienced email sending delays. As of 12:20 p.m. EST, the technical issue was resolved and as of 1 p.m. EST, all queued emails were successfully sent and email sending returned to normal. No emails were lost as a result of this technical issue -- only delayed in being sent to recipients.
If you have any additional questions, feel free to reach out to our Support Team at http://www.pardot.com/help/