Javamail behind proxy

[Akhilesh Trivedi]

I am using javamail and behind a proxy.
The mail server, the proxy and the application all three are on same LAN.
If I use outlook to talk to my mail server, it works fine... however with javamail, the following sample code throws exception...

import java.io.*;
    import javax.mail.*;
    import javax.mail.internet.*;
    import javax.activation.*;
    
    public class SendApp {
        public static void send(String smtpHost, int smtpPort,
                                String from, String to,
                                String subject, String content)
                throws AddressException, MessagingException {
            // Create a mail session
            java.util.Properties props = new java.util.Properties();
            props.put("mail.smtp.host", smtpHost);
            props.put("mail.smtp.port", ""+smtpPort);
            
            Session session = Session.getDefaultInstance(props, null);
    
            // Construct the message
            Message msg = new MimeMessage(session);
            msg.setFrom(new InternetAddress(from));
            msg.setRecipient(Message.RecipientType.TO, new InternetAddress(to));
            msg.setSubject(subject);
            msg.setText(content);
           
            
    
            // Send the message
            Transport.send(msg);
        }
    
        public static void main(String[] args) throws Exception {
            // Send a test message
            send("<some ip here>", 25, "<my [e-mail]>", "<[e-mail]>",
                 "Hello!", "How are you?");
        }
    }
 

nested exception is:
javax.mail.MessagingException: Could not connect to SMTP host: <some ip here>, port: 25;
nested exception is:
java.net.SocketException: Software caused connection abort: connect
at javax.mail.Transport.send0(Transport.java:219)
at javax.mail.Transport.send(Transport.java:81)
at SendApp.send(SendApp.java:28)
at SendApp.main(SendApp.java:33)

[Paul Sturrock]

Does your proxy server allow the relaying of SMTP? Its going to have to to use JavaMail, and most don't.

[Akhilesh Trivedi]

Thanks paul. I see it this way, if my outlook express works fine, so should any other mail client, then why not it be my javamail application? Just disabled proxies from IE and outlook still works as is...

[Paul Sturrock]

Be careful. If you are talking about Exchange servers, Outlook Express does not use SMTP to connect to them, it uses MAPI.

Just disabled proxies from IE and outlook still works as is

The connection setting in IE and the Services defined in Outlook Express are unrelated.

However, if you can connect to an SMTP server via a proxy using an MUA that is actually using SMTP as its connection protocol (phew!) then JavaMail should be able to connect too. How do you know that Outlook is using a proxy? Looking at my version of Outlook, I can only define a mail server, not a proxy (of course the mail server I define may actually be a proxy, but I can't tell that from Outlook).

[Paul Clapham]

Are you sure the proxy is responsible for preventing you from connecting to port 25 on the mail server? I ask because some virus-prevention products (McAfee for sure and probably others) will block any outbound access to port 25, to prevent your computer from being used as a spam source. You should be able to turn that off in the product's configuration if that is your problem.