Question

What are the minimum SSL protocol versions that Dovecot 2.4 accepts?

Answer

Dovecot 2.4 supports TLSv1, TLSv1.1, TLSv1.2, TLSv1.3. The default value is set to TLSv1.2.

Please note that SSLv3 was deprecated in June 2015 due to critical security vulnerabilities. Dovecot dropped support for SSLv3 in version 2.4.

Additional information on Dovecot 2.4's "ssl_min_protocol" option can be found below via Dovecot's documentation:

All Settings | Dovecot CE - ssl_min_protocol