Resolved - Following the plan for permanently retiring support for TLSv1.0 and v1.1 we have concluded our initial temporary shutoff which began on Tuesday, January 21, 2020 at 11:00am until and through Wednesday, January 22 at 4:00pm.

As of January 22, 2020 at 4:00pm all systems are now running in full-compatibility mode, meaning that they are accepting TLSv1.0 and above.

The next step in retiring support for TLSv1.0 will begin on Tuesday, February 4, 2020 at 9:30am and will concluded at 11:30am the same day wherein any requests utilizing TLSv1.0 or TLSv1.1 will be rejected.

NOTE: All times are Mountain Time (MST) unless otherwise indicated.

NOTE: Our clients who are having the greatest difficulty are running Windows Server 2012r2 (or earlier) along with .Net 4.0 (or earlier). This Microsoft article (suggesting .Net 4.7) has been helpful for many:
https://docs.microsoft.com/en-us/dotnet/framework/network-programming/tls
Jan 23, 21:35 UTC

Resolved - Yesterday, Tuesday 21 January 2020 at 11:00 (AM) Eastern Time / 09:00 (AM) Mountain Time, in accordance with announcements we have made leading up to this day, we disabled acceptance of TLSv1.0 or TLSv1.1 connections to all of our APIs.

Yesterday, Tuesday 21 January 2020 at 18:00 Eastern Time and 16:00 Mountain Time, we re-enabled acceptance of TLSv1.0 or TLSv1.1 connections to all of our APIs. We did this as a courtesy to those who are still in the process of upgrading their clients to be able to connect using TLSv1.2 or greater.

Today we will be repeating this shutdown. Clients connecting to our APIs today between 11:00 (AM) Eastern Time / 09:00 (AM) Mountain Time and 18:00 Eastern Time / 16:00 Mountain Time will be rejected if their connections are using TLSv1.0 or TLSv1.1.

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
Jan 22, 16:09 UTC

Resolved - 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
Jan 20, 18:18 UTC