WHY WE MUST UPGRADE TLS?
The upgrade to TLS 1.2 or higher marks a ground breaking progress on current security policy representing a major departure from the TLS and secure encryption socket layer (SSL) protocols. ... Such issues have contributed to changes to many Internet security protocols
The industry is working to deprecate support for TLS 1.0 and 1.1 this year 2020. Google, Microsoft, Apple, and Mozilla have all announced that their browsers will no longer support TLS 1.0 and 1.1 as of March 2020.
From Microsoft
As of October 31, 2018, the Transport Layer Security (TLS) 1.0 and 1.1 protocols are deprecated for the Microsoft 365 service. The effect for end-users is minimal. This change has been publicized for over two years, with the first public announcement made in December 2017. This article is only intended to cover the Office 365 local client in relation to the Office 365 service but can also apply to on-premises TLS issues with Office and Office Online Server/Office Web Apps.
