Beginning tomorrow (Tuesday 21 January 2020 at 11:00 AM Eastern Time), our APIs will only accept client connections using TLSv1.2 or greater. Clients using TLSv1.0 or TLSv1.1 will no longer be able to connect.
An email broadcast was previously sent on this topic and all new signups since that broadcast have been notified as part of the new customer registration email message.
For more information see:https://smartystreets.com/blog/2019/10/removing-old-versions-of-tls
To see the version you are connecting with, see:https://test-tls.api.smartystreets.com