Simple Mail client that uses JavaMail for android

MailClient.java

import java.util.Properties;

import javax.mail.Authenticator;
import javax.mail.Folder;
import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.Store;

import android.support.annotation.Nullable;
import android.support.annotation.WorkerThread;
import android.util.Log;

public class MailClient extends Authenticator {

    private static final String TAG = MailClient.class.getSimpleName();

    private static final int IMAP_PORT = 993;
    private static final String IMAP_HOST = "Your mail server";
    private final MailUser mMailUser;

    /**
     * Creates a Basic mail client to check the user's passed in new messages
     *
     * @param MailUser
     */
    public MailClient(MailUser mailUser) {
        this.mMailUser = mailUser;
    }

    /**
     * Connects to the user inbox.<BR/>
     * <b>Should be called on a worker thread as it involves networks calls.</b>
     *
     * @return store the users virtual mail box
     */
    @WorkerThread
    @Nullable
    public Store connectInbox() {
        try {
            Properties props = getIMAPProperties();
            Session session = Session.getInstance(props, this);
            Store store = session.getStore("imaps");
            store.connect(IMAP_HOST, IMAP_PORT, mTwinMailUser.getEmailAddress(), mMailUser.getEmailPassword());
            return store;
        } catch (MessagingException e) {
            Log.e(TAG, e.getMessage(), e);
        }
        return null;
    }


    /**
     * Gets the users messages filtered on unread ones
     *
     * @param store
     * @return the number of unread messages
     * @throws MessagingException
     */
    public int getUnreadMessageCount(Store store) throws MessagingException {
        if (store == null) {
            return 0;
        }
        Folder inbox = store.getFolder("Inbox");
        return inbox.getUnreadMessageCount();
    }

    private Properties getIMAPProperties() {
        Properties props = new Properties();
        props.put("mail.imap.host", IMAP_HOST);
        if (BuildConfig.DEBUG) {
            props.put("mail.debug", "true");
        }
        props.put("mail.imap.auth", "true");
        props.put("mail.imap.starttls.enable", "true");
        props.put("mail.imap.port", IMAP_PORT);
        props.put("mail.imap.socketFactory.port", IMAP_PORT);
        props.put("mail.imap.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
        props.put("mail.imap.socketFactory.fallback", "false");
        return props;
    }
}