Problem
Please check the following steps If you cannot connect to your secured email server.
Solution
Please check the availability of the server after each step.
1) Go to {baseUrl}/admin/sendemailtopage-admin/sendemailtopage-admin.action and check "imaps"/"pop3s" is setted.
2) Check ports availability from Confluence to the email server and vice versa. Telnet is a suggested tool. Configure your firewall If you faced the issue.
3) Make "cacert" file with added the certificate of the email server by provided Instruction
Then update your setenv script with path to the "cacert" file:
{Confluence Install Directory}\bin\setenv.sh(bat) JVM_SUPPORT_RECOMMENDED_ARGS=-Djavax.net.ssl.trustStore="path to cacert file"
4) Update JDK
If provided steps don't resolve the issue, please go to {baseUrl}/admin/sendemailtopage-admin/sendemailtopage-admin.action "Download Log Files" and open ticket in our Service Desk and attach addon-log and atlassian-confluence.log.