Although these old versions (TLS 1.0 and TLS 1.1) are rarely used by clients, older versions of development tools still use it.

In order to prevent any communication issues, we strongly advise that:  

• Review and update any application that doesn’t support TLS 1.2 or newer in order to continue to use the Emarsys APIs.  
• Always use HTTPS to communicate with the Emarsys API.
• Ensure you connect to the API using secure cipher suites.

Microsoft, Apple and Google announced long ago the end of support for TLS 1.0 and TLS 1.1.  
All modern browsers and applications support TLS 1.2 and so does the vast majority of services, servers and applications.  
The usage of TLS 1.0 and 1.1 acts as a security risk and although these old protocols are still supported by some servers, their usage is mainly by outdated non-browser software.  
These old versions have cryptographic and implementation vulnerabilities and to provide all cryptographic services and protect your data, your customers’ data and our systems we can’t postpone this update.  

This change will be invisible. Most websites already support TLS 1.2 and any modern browser (any browser version released in the last five years) supports TLS 1.2.