邮件发不出去，急，大家帮忙呀。
public   static   void   StartSendMail(string   mailto,string   mailFrom,string   subject,string   mailBody)
{
MailMessage   objMessage=new   MailMessage();
//objMessage.To=mailto+ " < "+mailtoAddress+ "> ";
objMessage.To=mailto;
objMessage.From=mailFrom+ " <hr@sohu.com> ";
objMessage.Subject=subject;
objMessage.BodyFormat=MailFormat.Html;
objMessage.BodyEncoding=Encoding.GetEncoding( "GB2312 ");
objMessage.Body=mailBody;
objMessage.Fields.Add( "http://schemas.microsoft.com/cdo/configuration/smtpauthenticate ",   1);
objMessage.Fields.Add( "   http://schemas.microsoft.com/cdo/configuration/sendusername ",   "hr ");

objMessage.Fields.Add( "http://schemas.microsoft.com/cdo/configuration/sendpassword ",   "hr ");
SmtpMail.SmtpServer   =   "mail.sohu.com ";
SmtpMail.Send(objMessage);
}

------解决方案--------------------
服务器。。端口