高手救命，帮我看看这个异常
MailMessage   Message   =   new   MailMessage();
  Message.To.Add(new   MailAddress(this.TextBox1.Text));
  Message.Subject   =   this.TextBox2.Text;
  Message.Body   =   this.TextBox3.Text;
  Message.From   =   new   MailAddress(this.TextBox4.Text);
  SmtpClient   smtpClient   =   new   SmtpClient( "smtp.163.com ");
  //smtpClient.Credentials   =   new   NetworkCredential( "jaykoby@163.com ",   "8836652 ");
  smtpClient.UseDefaultCredentials   =   false;
  smtpClient.Send(Message);

异常发生在smtpClient.Send(Message);
Mailbox   name   not   allowed.   The   server   response   was:   authentication   is   required,smtp5,wKjRELArpABDDqdGOw+ZAg==.42102S2   1185353283

------解决方案--------------------
我也用过163的SMTP服务，不太好用，最好自己机器上配置一个SMTP
------解决方案--------------------
邮件服务器分为
SMTP 和　ESMTP
SMTP　不需要验证
ESMTP　需要验证，现今大多数采用ESMTP

所以你要先验证服务器