ASP.NET邮件接收问题

using System.Net.Mail;

string EmailStr = Email.Text;
SmtpClient _smtpClient = new SmtpClient();
_smtpClient.DeliveryMethod = SmtpDeliveryMethod.Network;//指定电子邮件发送方式
_smtpClient.Host = smtp;//指定SMTP服务器
_smtpClient.Credentials = new System.Net.NetworkCredential(name, pass);//用户名和密码

MailMessage _mailMessage = new MailMessage(address, EmailStr);
_mailMessage.Subject = "您在神州数码的邮箱验证码";//主题

string YangzhengMa = GetString(6);
Session["Yanzhengma"] = YangzhengMa;

_mailMessage.Body = YangzhengMa;//内容
_mailMessage.BodyEncoding = System.Text.Encoding.UTF8;//正文编码
_mailMessage.IsBodyHtml = true;//设置为HTML格式
_mailMessage.Priority = MailPriority.High;//优先级

try
{
_smtpClient.Send(_mailMessage);
Response.Write("<script>alert