[ISSUE-4072][Bug] Use SSL when checking alert email

[hutiefang76]

What changed

This fixes the alert email connection check for SSL SMTP settings.

The actual email sending path uses SSL-on-connect when SenderEmail.ssl is enabled, but SettingServiceImpl.checkEmail was enabling STARTTLS instead. That makes the check fail for SSL SMTP servers such as the case reported in #4072.

This patch extracts the JavaMail property building and makes checkEmail set mail.smtp.ssl.enable=true when SSL is selected. Plain SMTP keeps the existing behavior.

Tests

JAVA_HOME=$(/usr/libexec/java_home -v 17) ./mvnw -s /tmp/codex-empty-maven-settings.xml \
  -pl streampark-console/streampark-console-service -am \
  -DskipITs -DskipRat -DskipWeb -DfailIfNoTests=false \
  -Dtest=SettingServiceImplTest test

Also checked:

git diff --check

I used OpenAI Codex to help inspect the issue and prepare the patch, then reviewed the diff and ran the tests above locally.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud