Question

I have been working at home on Gmail-Imap-Api on the weekend. It was working Properly But when i returned to office and am trying here it throws exception.

    Properties props = System.getProperties();
    props.put("mail.store.protocol", "imaps");
    props.put("mail.smtp.auth", "true");

    try {
        boolean debug = false;
        Authenticator auth = new SMTPAuthenticator(
                "***", "***");

        Session session = Session.getInstance(props, auth);
        session.setDebug(debug);
        Store store = session.getStore("imaps");
        store.connect("imap.gmail.com", "***@gmail.com",
                "****");
    ......
    ......

This was working fine at home netwrok.
Now i thought i would add proxy and added these lines of code.

    System.setProperty("http.proxyHost", "****.com");
    System.setProperty("http.proxyPort", "8080");

Still it doesnt work and the exception is.

com.google.code.javax.mail.MessagingException: imap.gmail.com;
nested exception is:
java.net.UnknownHostException: imap.gmail.com
at com.google.code.com.sun.mail.imap.IMAPStore.protocolConnect(IMAPStore.java:665)
at com.google.code.javax.mail.Service.connect(Service.java:295)
at com.google.code.javax.mail.Service.connect(Service.java:176)
at openReports.OpenReportsProject.main(OpenReportsProject.java:43)
Caused by: java.net.UnknownHostException: imap.gmail.com
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:177)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:367)
at java.net.Socket.connect(Socket.java:524)
at com.sun.net.ssl.internal.ssl.SSLSocketImpl.connect(SSLSocketImpl.java:545)
at com.sun.net.ssl.internal.ssl.BaseSSLSocketImpl.connect(BaseSSLSocketImpl.java:141)
at com.google.code.com.sun.mail.util.SocketFetcher.createSocket(SocketFetcher.java:288)
at com.google.code.com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:231)
at com.google.code.com.sun.mail.iap.Protocol.<init>(Protocol.java:113)
at com.google.code.com.sun.mail.imap.protocol.IMAPProtocol.<init>(IMAPProtocol.java:110)
at com.google.code.com.sun.mail.imap.IMAPStore.protocolConnect(IMAPStore.java:632)
... 3 more

Answer 1

The proxy settings that you have entered will work only for HTTP connections. IMAP is a different protocol operating on a different port (993 in this case). If you are behind firewall, your firewall needs to allow connection to the external host:port AND the protocol. You need to request to your Network Administrator for this. Once the settings are in place you will be able to communicate to Gmail Imap server on default/specified port with specified protocol.