Asp.Net(C#)发送带有附件及显示图片的邮件

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Net.Mail;
using System.Text;

public partial class VJSDN_MAIL : System.Web.UI.Page
{
    /*
    发送带有附件及显示图片的邮件。
    http://www.csframework.com copyrights reserved 
    */       
   protected void Page_Load(object sender, EventArgs e)
   {
      //
   }
   
   protected void Button1_Click(object sender, EventArgs e)
   {
      //必须是域名内的地址
      string logoFile = Server.MapPath("~/images/vjsdn.png");
      
      this.SendEmail(logoFile);
   }
   
   public bool SendEmail(string logoFile)
   {
      //增加图片附件
      Attachment imgLogo = new Attachment(logoFile);
      imgLogo.Name = "vjsdn.png"; //定个名字
      imgLogo.NameEncoding = Encoding.UTF8;
      imgLogo.TransferEncoding = System.Net.Mime.TransferEncoding.Base64;
      imgLogo.ContentDisposition.Inline = true;
      imgLogo.ContentDisposition.DispositionType = System.Net.Mime.DispositionTypeNames.Inline;
      string cid = imgLogo.ContentId;
      
      bool ret = this.Send("webadmin@vjsdn.com", "请激活帐号.(by www.vjsdn.com)", "请激活帐号.(by www.vjsdn.com)", imgLogo, true);
      return ret;
   }
   
   public bool Send(string address, string subject, string body, Attachment attachment, bool isBodyHtml)
   {
      try
      {
         MailMessage mail = new MailMessage();
         mail.From = new MailAddress("yourmail@vjsdn.com"); //你的邮箱，用于发邮件
         mail.To.Clear();
         mail.To.Add(new MailAddress(address));
         mail.Body = body;
         mail.BodyEncoding = Encoding.UTF8;
         mail.SubjectEncoding = Encoding.UTF8;
         mail.Subject = subject;
         mail.IsBodyHtml = isBodyHtml;
         mail.Priority = System.Net.Mail.MailPriority.Normal;
         
         if (attachment != null) mail.Attachments.Add(attachment);
         
         SmtpClient smtp = new SmtpClient("mail.vjsdn.com", 25); //SMTP
         smtp.UseDefaultCredentials = true;
         smtp.DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network;
         
         //邮件帐号，及密码.注意增的邮件帐号和邮件密码
         smtp.Credentials = new System.Net.NetworkCredential("accountxxx", "pwdxxxx");
         smtp.Send(mail);
         return true;
      }
      catch
      {
         return false;
      }
   }
}