Drop support of obsolete encryption methods

From October 15, 2020, Office 365 (including Primary Mail Service) will stop supporting the obsolete encryption methods (TLS1.0 and TLS1.1).

Older software and mobile devices (including smartphones) that do not support TLS1.2 will not be able to connect. If you are unable to connect after this date, please check this point and update your software or change your device if necessary.

SMTP submission server of Primary Mail Service will also drop support of TLS1.0 and TLS1.1 on the same day.