M365 Changelog: TLS 1.0 and 1.1 retirement date in Office 365 to be October 15, 2020

MC218794 – We originally paused the retirement of TLS 1.0 and 1.1 in Office 365 (MC186218 June ’20) due to these unprecedented times. As companies have pivoted their supply chains and countries have started to re-open, we have re-established a retirement date for TLS 1.0 and 1.1 in Office 365 to be October 15, 2020. As previously communicated (MC126199 in Dec 2017, MC128929 in Feb 2018 and MC186827 in July 2019), we are moving all of our online services to Transport Layer Security (TLS) 1.2+ toprovide best-in-class encryption, and to ensure our service is more secure by default.

Note: If your organization has already taken steps to migrate from TLS 1.0 and 1.1 you can safely disregard this message.

Key Points:

• Major: Retirement
• Timing: October 15, 2020
• Action: update or replace client devices as appropriate

How this affects your organization:

Once this change takes affect, all connections to Office 365 using the protocols TLS 1.0 and TLS 1.1 will no longer work.

What you should do to prepare:

Update or replace clients and devices that rely on TLS 1.0 and 1.1 to connect to Office 365, prior to October 15, 2020.

Please click Additional Information to learn more. TLS 1.0 and 1.1 deprecation for Office 365Additional information