Getting mail from GMail into Java application using IMAP

Question

I want to access messages in GMail from a Java application using JavaMail and IMAP. Why am I getting a SocketTimeoutException?

Here is my code:

Properties props = System.getProperties();
props.setProperty("mail.imap.host", "imap.gmail.com");
props.setProperty("mail.imap.port", "993");
props.setProperty("mail.imap.connectiontimeout", "5000");
props.setProperty("mail.imap.timeout", "5000");

try {
  Session session = Session.getDefaultInstance(props, new MyAuthenticator());
  URLName urlName = new URLName("imap://[email protected]:[email protected]");
  Store store = session.getStore(urlName);
  if (!store.isConnected()) {
    store.connect();
  }
} catch (NoSuchProviderException e) {
  e.printStackTrace();
  System.exit(1);
} catch (MessagingException e) {
  e.printStackTrace();
  System.exit(2);
}

I set the timeout values so that it wouldn't take "forever" to timeout. Also, MyAuthenticator also has the username and password, which seems redundant with the URL. Is there another way to specify the protocol? (I didn't see it in the JavaDoc for IMAP.)

Answer 1

You have to connect to GMail using SSL only. Setting the following properties will force that for you.

props.setProperty("mail.imap.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
props.setProperty("mail.imap.socketFactory.fallback", "false");

Answer 2

In JavaMail, you can use imaps as the URL scheme to use IMAP over SSL. (See SSLNOTES.txt in your JavaMail distribution for more details.) For example, imaps://username%[email protected]/INBOX.

Similarly, use smtps to send emails via Gmail. e.g., smtps://username%[email protected]/. Again, read SSLNOTES.txt for more details. Hope it helps!

Answer 3

Using imaps was a great suggestion. Neither of the answers provided just worked for me, so I googled some more and found something that worked. Here's how my code looks now.

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", "<username>@gmail.com", "<password>");
  ...
} catch (NoSuchProviderException e) {
  e.printStackTrace();
  System.exit(1);
} catch (MessagingException e) {
  e.printStackTrace();
  System.exit(2);
}

This is nice because it takes the redundant Authenticator out of the picture. I'm glad this worked because the SSLNOTES.txt make my head spin.

Answer 4

Check http://g4j.sourceforge.net/. There is a minimal gmail client built using this API.

Answer 5

If you'd like more sample code on using JavaMail with Gmail (e.g. converting Gmail labels to IMAP folder names, or using IMAP IDLE), do check out my program GmailAssistant on SourceForge.

Answer 6

URLName server = new URLName("imaps://:@imap.gmail.com/INBOX");

Answer 7

Thanks

Great help Dave

Answer 8

I used following properties to get the store and It works well.

"mail.imaps.host" : "imap.gmail.com"
"mail.store.protocol" : "imaps"
"mail.imaps.port" : "993"

Answer 9

I have a problems, when we run the program comming this error "Unable to locate provider for protocol: imaps"

Answer 10

roshan, you need to have JSSE installed to use SSL with Java