使用Javamail通过imap访问gmail（位于代理之后）

Question

I am using code from on the earlier threads(have pasted the code below as well):

Getting mail from GMail into Java application using IMAP

How do I make this code work if I am behind a proxy?

The connection is getting timed out, I have tried to search for a solution but to no avail.

public static void main(String args[]) {

    Properties props = System.getProperties();
    props.setProperty("mail.store.protocol", "imaps");
        try {
            Session session = Session.getDefaultInstance(props, null);
            Store store = session.getStore("imaps");
            store.connect("imap.gmail.com", email, password);
            System.out.println(store);

            Folder inbox = store.getFolder("Inbox");
            inbox.open(Folder.READ_ONLY);
            Message messages[] = inbox.getMessages();
            for(Message message:messages) {
            System.out.println(message);
        }
    } catch (NoSuchProviderException e) {
        e.printStackTrace();
        System.exit(1);
    } catch (MessagingException e) {
        e.printStackTrace();
        System.exit(2);
    }

}

Thanks, Chris.

Answer 1

Behind the proxy doesn't stop you to connect to IMAP

There could be 2 reasons

1. The IMAP port is block by your network administrator
2. your IP is blocked/banned by Google

Thanks

Answer 2

Check out the Java Mail FAQ :

Q: How do I configure JavaMail to work through my proxy server?

A: JavaMail does not currently support accessing mail servers through a web proxy server. One of the major reasons for using a proxy server is to allow HTTP requests from within a corporate network to pass through a corporate firewall. The firewall will typically block most access to the Internet, but will allow requests from the proxy server to pass through. In addition, a mail server inside the corporate network will perform a similar function for email, accepting messages via SMTP and forwarding them to their ultimate destination on the Internet, and accepting incoming messages and sending them to the appropriate internal mail server.

If your proxy server supports the SOCKS V4 or V5 protocol (http://www.socks.nec.com/aboutsocks.html, RFC1928) and allows anonymous connections, you can tell the Java runtime to direct all TCP socket connections to the SOCKS server. See the Networking Properties guide for the latest documentation of the socksProxyHost and socksProxyPort properties. These are system-level properties, not JavaMail session properties. They can be set from the command line when the application is invoked, for example: java -DsocksProxyHost=myproxy .... This facility can be used to direct the SMTP, IMAP, and POP3 communication from JavaMail to the SOCKS proxy server. Note that setting these properties directs all TCP sockets to the SOCKS proxy, which may have negative impact on other aspects of your application.

Without such a SOCKS server, if you want to use JavaMail to directly access mail servers outside the firewall, the firewall will need to be configured to allow such access. JavaMail does not support access through a HTTP proxy web server.