想用线程做个东西,邮件用10个线程发10000个邮件如何写这个代码呢

delegate void SetTextCallback(string text); 
private void SetText(string text) 
{ 
if (this.textBox1.InvokeRequired) 
{ 
SetTextCallback d = new SetTextCallback(SetText); 
this.Invoke(d, new object[] { text }); 
} 
else 
{ 
this.textBox1.Text = text; 
} 
} 
private void thread1(object para) 
{ 
      SetText("....."); 
} 
private void button1_Click(object sender, EventArgs e) 
{ 
     //如果要参数 
      //定义参数para 
     Thread w0 = new Thread(new ParameterizedThreadStart(thread1)); 
     w0.Start(para); 
}