通过smtp使用Java代码发送电子邮件

Question

I'm getting this below error and timeout exception.

enter code:

Properties props = new Properties();  
props.put("mail.smtp.auth", "true");
props.put("mail.smtp.starttls.enable", "true");
props.put("mail.smtp.host","smtp.gmail.com"); 
props.put("mail.smtp.port", "587");
props.put("mail.debug", "true");

DEBUG SMTP: trying to connect to host "smtp.gmail.com", port 587, isSSL true Exceptioninthread"main"java.lang.RuntimeException:com.sun.mail.util.MailConnectException: Couldn't connect to host,port:smtp.gmail.com, 587; timeout -1.

Answer 1

private static void sendFromGMail(String from, String pass, String[] to, String subject, String body) {
    Properties props = System.getProperties();
    String host = "smtp.gmail.com";
  //String host="localhost";
  //props.put("mail.smtp.ssl.trust", "smtp.gmail.com");
    props.put("mail.smtp.starttls.enable", "true");
  //props.put("mail.smtp.host", host);
    props.put("mail.smtp.ssl.trust", host);
    props.put("mail.smtp.user", from);
    props.put("mail.smtp.password", pass);
    props.put("mail.smtp.port", "587");//587
    props.put("mail.smtp.auth", "true");
  //System.out.println("1");

    Session session = Session.getDefaultInstance(props);
    MimeMessage message = new MimeMessage(session);

    try {
         //System.out.println("2");

        message.setFrom(new InternetAddress(from));
        InternetAddress[] toAddress = new InternetAddress[to.length];

        // To get the array of addresses
        for( int i = 0; i < to.length; i++ ) {
            toAddress[i] = new InternetAddress(to[i]);
        }

        for( int i = 0; i < toAddress.length; i++) {
            message.addRecipient(Message.RecipientType.TO, toAddress[i]);
        }

         //System.out.println("3");

        message.setSubject(subject);
        message.setText(body);
        // System.out.println("4");

        Transport transport = session.getTransport("smtp");
        // System.out.println("5");

        transport.connect(host, from, pass);
        transport.sendMessage(message, message.getAllRecipients());
        transport.close();
        //System.out.println("sent successfully...");
    }
    catch (AddressException ae) {
        ae.printStackTrace();
    }
    catch (MessagingException me) {
        me.printStackTrace();
    }
  }

calling above method and pass these parameters to the method

private static String USER_NAME = "xxxx";  // username "@gmail.com")
private static String PASSWORD = "xxxx"; // password
private static String RECIPIENT = "xxx@gmail.com";

public static void main(String[] args) {
    String from = USER_NAME;
    String pass = PASSWORD;
    String[] to = { RECIPIENT }; // list of recipient email addresses
    String subject = "Java send mail example";
    String body = "Welcome to JavaMail!";

    sendFromGMail(from, pass, to, subject, body);
}

And i used following jar files ,

java-mail-1.4.4
javamail-smtp-1.4.2
pop3
mail-6.0.0-sources

Answer 2

Ignore most of the other answers and comments, which are wrong or irrelevant. Many of them include these common JavaMail mistakes . Your original code was fine.

See the JavaMail FAQ for GMail instructions .

Most likely you can't connect because there is some firewall preventing direct access. The JavaMail FAQ has connection debugging tips .

If you can't connect directly and need to connect through a proxy server, the JavaMail FAQ also covers that .