We are currently experiencing an unexpected issue with our email cluster causing intermittent connectivity issues to the mail servers. Our engineers are currently investigating this issue.
Update @ Mon Feb 12 14:49:19 GMT 2018: Our operations team is continuing to work on the issues impacting the email cluster performance.
Update @ Mon Feb 12 16:59:21 MST 2018: The issues we were experiencing are now resolved. Thank you for your patience in this matter.