in src/main/java/org/apache/sling/commons/messaging/mail/internal/SimpleMailService.java [160:171]
private void configure(final SimpleMailServiceConfiguration configuration) {
threadPoolManager.release(threadPool);
threadPool = threadPoolManager.get(configuration.threadpool_name());
final Properties properties = new Properties();
properties.setProperty(MAIL_SMTPS_SSL_CHECKSERVERIDENTITY, Boolean.toString(configuration.mail_smtps_ssl_checkserveridentity()));
final String from = configuration.mail_smtps_from();
if (Objects.nonNull(from) && !from.isBlank()) {
properties.setProperty(MAIL_SMTPS_FROM, from.trim());
}
this.properties = properties;
}