We traced the issue to an updated dependency and the fix is live. If you notice any outstanding issues, please let us know at email@example.com
Posted 12 days ago. Apr 12, 2019 - 17:15 PDT
This afternoon's deploy caused a regression blocking email sending from the app in some accounts. Emails sent and received via native email clients are not experiencing any disruption. A patch is enroute to fix the problem.