JavaMail reading recent unread mails using IMAP

Question

I have a requirement to retrieve unread mails from Gmail. I am using Java Mail API. By default, this API retrieves mails from the oldest to newest. But I need to retrieve recent mails first. Is it possible? Thanks in advance.

Forsyth

Answer 1

Here is example. Do not forget to add javax.mail in your classpath.

import javax.mail.*;
import javax.mail.search.FlagTerm;
import java.util.*;

public class GmailFetch {

  public static void main( String[] args ) throws Exception {

    Session session = Session.getDefaultInstance(new Properties( ));
    Store store = session.getStore("imaps");
    store.connect("imap.googlemail.com", 993, "[email protected]", "password");
    Folder inbox = store.getFolder( "INBOX" );
    inbox.open( Folder.READ_ONLY );

    // Fetch unseen messages from inbox folder
    Message[] messages = inbox.search(
        new FlagTerm(new Flags(Flags.Flag.SEEN), false));

    // Sort messages from recent to oldest
    Arrays.sort( messages, ( m1, m2 ) -> {
      try {
        return m2.getSentDate().compareTo( m1.getSentDate() );
      } catch ( MessagingException e ) {
        throw new RuntimeException( e );
      }
    } );

    for ( Message message : messages ) {
      System.out.println( 
          "sendDate: " + message.getSentDate()
          + " subject:" + message.getSubject() );
    }
  }
}

Kwangtung

Answer 2

Make sure to use the IMAP protocol, as it supports for flagging.

Do following changes to your code:

1. replace inbox.open( Folder.READ_ONLY ); by inbox.open( Folder.READ_WRITE );

2. Then after reading the message, set the flag like so:

   message.setFlag(Flags.Flag.SEEN, true);
   

Full example:

    import javax.mail.*;
    import javax.mail.search.FlagTerm;
    import java.util.*;

    public class GmailFetch {

      public static void main( String[] args ) throws Exception {

        Session session = Session.getDefaultInstance(new Properties( ));
        Store store = session.getStore("imaps");
        store.connect("imap.googlemail.com", 993, "[email protected]", "password");
        Folder inbox = store.getFolder( "INBOX" );
        inbox.open( Folder.READ_WRITE );

        // Fetch unseen messages from inbox folder
        Message[] messages = inbox.search(
            new FlagTerm(new Flags(Flags.Flag.SEEN), false));

        // Sort messages from recent to oldest
        Arrays.sort( messages, ( m1, m2 ) -> {
          try {
            return m2.getSentDate().compareTo( m1.getSentDate() );
          } catch ( MessagingException e ) {
            throw new RuntimeException( e );
          }
        } );

        for ( Message message : messages ) {
          System.out.println( 
              "sendDate: " + message.getSentDate()
              + " subject:" + message.getSubject() );
              message.setFlag(Flags.Flag.SEEN, true);
        }
      }
    }

Interclavicle

Why is this needed? There is an accepted answer which is three years old... – Willwilla

I agree with you @NicoHaase, I think this poster was trying to say you should set the SEEN flag as true so that it is marked as read so that the message isn't requested the next time this program runs. – Freund

How to fetch unread mails only, seems search method is not accepting the Flag now. – Gabfest

Answer 3

I think this might help to access read/unread/recent mails change your variables according to your needs.

// search for all "unseen" messages

Flags seen = new Flags(Flags.Flag.SEEN);// try changing this SEEN to RECENT 

// set it true or false for seen & unseen mail

FlagTerm unseenFlagTerm = new FlagTerm(seen, false)
Message messages[] = inbox.search(unseenFlagTerm);

Heavyweight

Answer 4

JavaMail gives you an array of Message objects. The messages are in the order received. If you want to look at the most recently received messages first, go through the array in the reverse order. If you want to look at the most recently sent messages first, you'll need to sort the array, as described in the other answer.

Behave

I think I know what his problem is. At least it sounds like one I had: If you want to update the screen promptly upon user action, then most IMAP servers' FETCH response order is not good. "Highest UID first" would be better than "lowest UID first". But this is not something Javamail can solve. – Stambaugh