都要用到JBuilder里的一个组件，
你可以去JBuilder目录下拷，
或自己用JDK的组件改一下
NO 1:这个程序调用Foxmail发送信件
/*这个程序要用到Jbuilder的几个类*/import java.awt.*;import java.awt.event.*;import java.applet.*;import borland.jbcl.layout.*;import borland.jbcl.control.*;import java.net.*;public class EmailApplet extends Applet{Button button;TextField textField;public EmailApplet(){}public void init(){try{jbInit();}catch(Exception e){e.printStackTrace();}}//end of init()public void jbInit()throws Exception{setLayout(new BorderLayout());button=new Button("sendmail");textField=new TextField();add("North",textField);add("South",button);}//end of jbInit()public boolean action(Event e,Object arg){if(arg.equals("sendmail")){try{/*注意哦,这里是主要代码!!*/String mailto=textField.getText();URL url=new URL(mailto);AppletContext ac=this.getAppletContext();ac.showDocument(url);}catch(Exception e2){System.out.println(e2.toString());}}//end of ifelse{return super.action(e,arg);}return true;}//end of action()}//end of EmailAppletNO 2:这个程序直接发送信件:import borland.jbcl.layout.*;import borland.jdbl.*;import java.awt.*;import java.applet.Applet;import java.util.StringTokenizer;import java.net.Socket;import java.io.PrintStream;import java.lang.Exception;import java.awt.event.ActionEvent;public class MailApplet extends Applet{boolean isStandalone=false;PaneLayout panelLayout1=new PaneLayout();panel panel1=new Panel();Label label1=new Label();XYLayout xYLayout1=new XYLayout();Label Label2=new Label();TextField textField1=new TextField();TextField textField2=new TextField();Label lable3=new Label();TextArea textArea1=new TextArea();Button button1=new Button();Button button2=new Button();private int SMTP_PORT=25;Frame. frame=new Frame();Color bgcolor=null;String send="";String get="";public MailApplet(){}public void init(){try{int c1=Integer.parseInt(getParameter("color1"));int c2=Integer.parseInt(getParameter("color2"));int c3=Integer.parseInt(getParameter("color3"));bgcolor=new Color(c1,c2,c3);SMTP_PORT=Integer.parseInt(getParameter("port"));send=getParameter("send");get=getParameter("get");jbInit();}catch(Exception e){e.printStackTrace();}}//end of init()/*Component initialization*/private void jbInit()throws Exception{this.setSize(new Dimension(332,280));panel1.setBackground(bgcolor);label1.setAlignment(2);label1.setText("收信人地址:");label2.setAlignment(2);label2.setText("寄信人地址:");label3.setAlignment(2);label3.setText("内容:");button1.setLabel("发 送");button1.addActionListener(new MailApplet_button1_actionAdapter(this));button2.setLabel("清 除");button2.addActionListener(new MailApplet_button2_actionAdapter(this));panel1.setLayout(xYLayout);this.setLayout(panelLayout1);thsi.add(panel1,new PaneConstraints("panel1","panel1",PaneConstraints.ROOT,1.0f));panel1.add(label1,new XYConstraints(10,5,80,20));panel1.add(label2,new XYConstraints(10,30,80,20));panel1.add(textField1,new XYConstraints(95,5,200,20));panel1.add(textField2,new XYConstraints(95,30,200,20));panel1.add(label3,new XYConstraints(10,60,80,20));panel1.add(textArea1,new XYConstraints(10,80,300,150));panel1.add(button1,new XYConstraints(50,240,80,25));panel1.add(button2,new XYConstraints(160,240,80,25));textField1.setText(get);textField2.setText(send);}//end of jbInit()public String getAppletInfo(){return "Applet Information";}public String[][] getParameteInfo(){return null;}void sendmail(){String sender=textField2.getText();String geter=textField1.getText();String memo=textArea1.getText();StringTokenizer st=new StringTokenizer(sender,"@");int count=st.countTokens();if(count!=2){MessageDialog mdlg=new MessageDialog(frame,"邮件地址错误","你的发信人地址错误，请确认后重新发送!!",1);mdlg.show();textField2.selectAll();return;}String senderName=st.nextToken();String senderHost=st.nextToken();st=new StringTokenizer(geter,"@");count=st.countTokens();if(count!=2){MessageDialog mdlg=new MessageDialog(frame,"邮件地址错误","你的收信人地址错误，请确认后重新发送!!",1);mdlg.show();textField1.selectAll();return;}String geterName=st.nextToken();String geterHost=st.nextToken();try{Socket s=new Socket(geterHost,SMTP_PORT);PrintStream ut=new PrintStream(s.getOutputStream());out.println("HELLO:"+senderHost);/*邮件服务器不认证读者所输SMTP是否正确*/out.println("MAIL FORM.:"+senderName);out.println("RCPT TO:"+geterName);out.println("DATA");out.println(memo);out.println("./nQUIT");MessageDialog mdlg=new MessageDialog(frame,"邮件地址正确","恭喜，您的邮件已经成功发送",1);mdlg.show();}catch(Exception e){System.out.println(e.toString());MessageDialog mdlg=new MessageDialog(frame,"邮件发送失败",e.toString(),1);//"邮件发送出错，请确认合重新发送!",1);mdlg.show();return;}}//end of sendmail()void button1_actionPerformed(ActionEvent e){sendmail();textArea1.setText("");}void button2_actionPerformed(ActionEvent e){textField1.setText("");textFIeld2.setText("");textArea1.setText("");}}//end of MailAppletclass MailApplet_button1_actionAdapter implements java.awt.event.ActionListener{MailApplet adaptee;MailApplet_button1_actionAdapter(MailApplet adaptee){this.adaptee=adaptee;}public void actionPerformed(ActionEvent e){adaptee.button1_actionPerformed(e);}}//end of thisclass MailApplet_button2_actionAdapter implements java.awt.event.ActionListener{MailApplet adaptee;MailApplet_button2_actionAdapter(MailApplet adaptee){this.adaptee=adaptee;}public void actionPerformed(ActionEvent e){adaptee.button2_actionPerformed(e);}}//end of this
