Getting mail from GMail into Java application using IMAP

JavaGmailJakarta MailImap

Java Problem Overview


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 have 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.)

Java Solutions


Solution 1 - Java

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.

Solution 2 - Java

You need to use the following properties for imaps:

props.setProperty("mail.imaps.host", "imap.gmail.com");
props.setProperty("mail.imaps.port", "993");
props.setProperty("mail.imaps.connectiontimeout", "5000");
props.setProperty("mail.imaps.timeout", "5000");

Notices it's "imaps", not "imap", since the protocol you're using is imaps (IMAP + SSL)

Solution 3 - Java

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!

Solution 4 - Java

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");

Solution 5 - Java

Here is what worked for my team and I, given a classic account [email protected] and a business account [email protected] :

            final Properties properties = new Properties();
            properties.put("mail.imap.ssl.enable", "true");

            imapSession = Session.getInstance(properties, null);
            imapSession.setDebug(false);
            imapStore = imapSession.getStore("imap");

            imapStore.connect("imap.gmail.com", USERNAME, "password");

with USERNAME = "nickname" in the classic case, and USERNAME = "[email protected]" in the business account case.

In the classic case, don't forget to lower the account security here : https://www.google.com/settings/security/lesssecureapps

In both cases check in GMail Settings => Forwarding POP / IMAP if IMAP is enabled for the account.

Hope it helps!

To go further :

Solution 6 - Java

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.

Solution 7 - Java

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

Solution 8 - Java

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"

Solution 9 - Java

URLName server = new URLName("imaps://<gmail-user-name>:<gmail-pass>@imap.gmail.com/INBOX");

Solution 10 - Java

You need to have JSSE installed to use SSL with Java

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