Java таймер Swing

Your task likely only needs to report results on the event thread (EDT) but do the actual work in a background thread at some periodic rate.

ScheduledExecutorService is EXACTLY what you want. Just remember to update the state of your UI on the EDT via SwingUtility.invokeLater(...)

У меня работает эта простая программа:

import java.awt.event.*;
import javax.swing.*;

public class Test {
    public static void main(String [] args) throws Exception{
        ActionListener taskPerformer = new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                //...Perform a task...

                System.out.println("Reading SMTP Info.");
            }
        };
        Timer timer = new Timer(100 ,taskPerformer);
        timer.setRepeats(false);
        timer.start();

        Thread.sleep(5000);
    }
}

I'm guessing from the log statement that you're doing some sort of SMTP operation. I think I'm right in saying the java.swing.Timer is intended for UI related timed operations, hence why it needs and EDT running. For more general operations you should use java.util.Timer.

This article is linked from the JavaDocs - http://java.sun.com/products/jfc/tsc/articles/timer/