code: private void logSession(Session session, TransportStrategy transportStrategy) {
  		final String logmsg = "starting mail session (host: %s, port: %s, username: %s, authenticate: %s, transport: %s)";
  		Properties properties = session.getProperties();
  		logger.debug(String.format(logmsg, properties.get(transportStrategy.propertyNameHost()),
  				properties.get(transportStrategy.propertyNamePort()), properties.get(transportStrategy.propertyNameUsername()),
  				properties.get(transportStrategy.propertyNameAuthenticate()), transportStrategy));
  	}
docs: Simply logs host details, credentials used and whether authentication will take place and finally the transport protocol used.