Properties props = new Properties(); props.put("mail.smtp.starttls.enable","true"); props.put("mail.smtp.auth", "true"); // If you need to authenticate // Use the following if you need SSL props.put("mail.smtp.socketFactory.port", d_port); props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory"); props.put("mail.smtp.socketFactory.fallback", "false"); javax.net.ssl.SSLException: Unrecognized SSL message, plaintext connection? java.util.Properties props = new java.util.Properties(); props.put("mail.smtp.starttls.enable", "true"); props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");