Java connecting to localhost SMTP server

Question

What is wrong with this code? I'm trying to send a email on my localhost with hMailServer, but it is not working. While this code is working for the Gmail SMTP server.. I might think the error is in my hMailServer, but I can't find it..

    try{
    String host = "127.0.0.1";
    String from = "account@127.0.0.1";
    String pass = "1q2w#E$R";
    Properties props = System.getProperties();
    props.put("mail.smtp.starttls.enable", "true"); // added this line
    props.put("mail.smtp.host", host);
    props.put("mail.smtp.user", from);
    props.put("mail.smtp.password", pass);
    props.put("mail.smtp.port", "25");
    props.put("mail.smtp.auth", "true");

    String[] to = {"test@test.com"}; // added this line

    Session session = Session.getDefaultInstance(props, null);
    MimeMessage message = new MimeMessage(session);
    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++ ) { // changed from a while loop
        toAddress[i] = new InternetAddress(to[i]);
    }
    for( int i=0; i < toAddress.length; i++) { // changed from a while loop
        message.addRecipient(Message.RecipientType.TO, toAddress[i]);
    }
    message.setSubject("sending in a group");
    message.setText("Welcome to JavaMail");
    Transport transport = session.getTransport("smtp");
    transport.connect(host, from, pass);
    transport.sendMessage(message, message.getAllRecipients());
    transport.close();
    }
    catch (Exception e) {
        e.printStackTrace();
    }

This is the error I'm getting:

    javax.mail.MessagingException: Could not connect to SMTP host: 127.0.0.1, port: 25;
nested exception is:
    java.net.SocketException: Permission denied: connect
    at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1213)
    at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:311)
    at javax.mail.Service.connect(Service.java:233)
    at javax.mail.Service.connect(Service.java:134)
    at nl.company.cms.login.emailservice.TestMail.main(TestMail.java:71)

I'm using hMailServer..

Answer 1

If you are using Java 7 then I would try adding this as a JVM parameter when you start your application:

-Djava.net.preferIPv4Stack=true

This may be necessary because Java is now trying to use IPv6 so we need to tell it to prefer the IPv4 stack instead.

Answer 2

如果您使用的是Xampp，请确保您的计算机上的计算机上正在运行Mercury，因为如果未启动水银，则端口25将无法与javaMail一起使用。

Answer 3

I confirm that only this parameter "-Djava.net.preferIPv4Stack=true", written in the catalina.bat of Tomcat, helped me to send an email from my Spring web app into my local hMailServer instance. Enviroment: Windows 8, Java 7u60.

Answer 4

I can confirm that by only implementing the suggestion provided by @Quantas of adding parameter "-Djava.net.preferIPv4Stack=true" in the "run configurations" in ECLIPSE, my problem of getting exception mail.Messaging Exception has been resolved now.

From last 2 days i was getting following exception while using " Fake SMTP mail server " to trap the mails sending out from my application running in eclipse.

javax.mail.MessagingException: Could not connect to SMTP host: localhost, port: 25;

Now the problem have been completely resolved by just putting this little piece of code into "VM ARGUMENTS" in "run configurations" of ECLIPSE LUNA

-Djava.net.preferIPv4Stack=true

As shown in snapshot below

This suggests the java to prefer using IPV4 stack instead of IPV6 (which it prefers previously)

Answer 5

I can confirm that only adding the VM argument for Tomcat :

-Djava.net.preferIPv4Stack=true

I could send a fake mail with "Fake SMTP Server" on my localhost from my webapp through JavaMail API