If you had problems receiving emails or opening attachments with Gmail yesterday, you weren't the only one. Google says that yesterday's Gmail outage delayed 29 percent of all emails sent from 8:54AM to roughly 7:00PM ET, with an average delay time of 2.6 seconds. But one and a half percent of emails saw a much greater backup yesterday, with delays of longer than two hours. It's hard to know how many messages were actually delayed, as Google doesn't provide data on its daily email volume, and even if estimates are available, traffic fluctuates widely hour by hour. Gmail does have over 425 million active users.

Google says that the delays were due to a dual network error, in which two separate failures knocked out some of Gmail's redundancy. While Google explains that its employees were immediately alerted of the errors, it took roughly seven hours for the teams to "repurpose additional capacity" and handle much the backlog of emails that had piled up. Services didn't return to full capacity for another three hours. The company says it is "taking steps to ensure that there is sufficient network capacity" and it will "make Gmail message delivery more resilient to a network capacity shortfall." The errors yesterday were the first major outage for the service since an estimated 5 million users lost service in spring of last year.