SMTP on both the incoming network servers, mx1 and mx2, and the client mail server, mail.eskimo.com, was down from approximately 13:20-13:25 PST on January 20th, 2014.

The outage resulted from an update to clamav-milter which overwrote a start-up script removing some necessary local customizations and causing the start of the newly updated clamav-milter to fail.

I checked the logs immediately after installing the updates so this was discovered and corrected within about five minutes.  I apologize for the brief interruption.