Though the scheduled downtime is 6:30am to 7am, we expect actual downtime to be less.
A new SSL certificate with different intermediate SSL certificates is being installed.
UPDATE
[2016-09-07 06:32:54 | mark kraitchman]
Outgoing smtp service resumed on gateway.eecs September 7, 2016 06:32 with a new SSL certificate.
Resolved as of 2016-09-07 06:32:00