Bamboo without TLS 1.2 select option for SMTP mail server configuration

Issue Summary

Bamboo fails to communicate with SMTP servers using TLS. Reported issue:

javax.mail.MessagingException: Could not convert socket to TLS; nested exception is: javax.net.ssl.SSLHandshakeException: No appropriate protocol (protocol is disabled or cipher suites are inappropriate)

Steps to Reproduce

1. Java 8u292+ and JDK 11.0.11+ in Bamboo 8+ - Openssl had TLS 1.0 and 1.1 disabled
2. Navigate as Bamboo Admin to Cog >> Overview >> Mail server.
3. Create or edit an existing configuration there and check the option "Use TLS".
4. Define Bamboo system or e.g. build notifications (for testing).

Expected Results

Notifications sent out from Bamboo should be encrypted in TLS 1.2 since TLS 1.0 is well known for security vulnerabilities. 

Actual Results

Check or filter the emails sent from Bamboo and find them encrypted in TLS 1.0.

Workaround

Add the system property below:

-Dmail.smtp.ssl.protocols=TLSv1.2

Following Configuring your system properties