Update: The service disruption started at about 1:00 pm EST and resolved at about 2:00 pm EST.
The practical impact of this in most cases was that if a Comcast subscriber attempted to access web interface using HTTPS that attempt was likely to fail.
As far as we can tell, this issue did not impact any unencrypted protocols like HTTP or SMTP, so most outgoing emails and incoming clicks/opens were unaffected.
The problem was resolved on its own.
Comcast users may have intermittent difficulty in accessing the Inboxfirst web interface due to a localized Comcast outage near the data center.
Update – Deliverability has made progress with the Microsoft team. Bounces are coming down. The initial find is the Microsoft spam algorithm incorrectly flagged IP addresses as “spammy” due to the mail stream increases beyond the threshold’s limits. We will continue to mitigate with them until all mail is flowing freely again.
Investigating – We are suddenly seeing high bounce rates coming from Microsoft accounts (hotmail.com, msn.com, outlook.com, live.com) tonight. Our deliverability team is currently in communication with Microsoft to determine the cause of this.
Updating – The large queues are now processing.
Investigating – Our team is investigating reports of emails being stuck in the queue. Our Operations team is looking at this with their highest priority.
Update 10/17/2015: All Campaigns should be deploying as expected at this point.
We are receiving reports that Campaigns stopped deploying around 9:00 am EST. Our engineers are investigating.
Resolved 10/16/2015: Cox.net have fixed their mail server issues and Cox.net mail is now flowing normally.
Update 10/16/2015: Cox.net is having trouble with their mail servers. Mail is flowing intermittently at this point.
Our Deliverability team is looking into reports of increased Cox.net deferrals and possible failures.