MainActivity.java

package com.example.javamailapp;

import android.app.Activity;
import android.util.Log;
import android.view.View;
import android.os.Bundle;
import android.widget.*;

import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.Store;
import java.util.Properties;
import javax.activation.CommandMap;
import javax.activation.MailcapCommandMap;

public class MainActivity extends Activity {
	RelativeLayout layout;

    public static void connect(String host, String user, String passwd) {
        Thread connector = new Thread(new Runnable() {
            public void run() {
                try {
		    MailcapCommandMap mc = (MailcapCommandMap) CommandMap.getDefaultCommandMap();
                    mc.addMailcap("text/html;; x-java-content-handler=com.sun.mail.handlers.text_html");
                    mc.addMailcap("text/xml;; x-java-content-handler=com.sun.mail.handlers.text_xml");
                    mc.addMailcap("text/plain;; x-java-content-handler=com.sun.mail.handlers.text_plain");
                    mc.addMailcap("multipart/*;; x-java-content-handler=com.sun.mail.handlers.multipart_mixed");
                    mc.addMailcap("message/rfc822;; x-java-content-handler=com.sun.mail.handlers.message_rfc822");
                    CommandMap.setDefaultCommandMap(mc);

                    Properties properties = new Properties();

                    properties.put("mail.store.protocol", "imaps");
                    // properties.put("mail.pop3.port", "995");
                    // properties.put("mail.pop3.starttls.enable", "true");
                    Session emailSession = Session.getDefaultInstance(properties);

                    Store store = emailSession.getStore("imaps");
                    store.connect(host, user, passwd);
                    Log.w("JavaMailApp", "Connection successful!");
                } catch (MessagingException e) {
                    Log.e("JavaMailApp", "error", e);
                }
            }
        });

        connector.start();
    }
	
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        layout = (RelativeLayout)RelativeLayout.inflate(this, R.layout.activity_main, null);
        setContentView(layout);

        String host = "imap.gmail.com";
        String user = "<your-name>@gmail.com";
        String passwd = "<your-password>";
        connect(host, user, passwd);
	}
}