.net发送带图片格式Email

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net.Mail;

 public class Mail
    {
        public void sendMail(string[] to, string[] cc, string subject, string body,string attachfile)
        {
            MailMessage mail = new MailMessage();
            mail.From = new MailAddress("abc@def.com");
            if (to != null)
                foreach (string _to in to)
                {
                    if (_to != "")
                    {
                        mail.To.Add(_to);
                    }
                }

            if (cc != null)
                foreach (string _cc in cc)
                {
                    if (_cc != "")
                    {
                        mail.CC.Add(_cc);
                    }
                }
            //""前加@，""内的内容就不用改了
            attachFile("E:\\test\\class\\Study\\studyWebApplication\\BLL\\office\\picture\\head.jpg", "head", 0,true,ref mail);
            attachFile(@"E:\test\class\Study\studyWebApplication\BLL\office\picture\taile.jpg", "taile", 1, true, ref mail);
            if (attachfile != "")
            {
                attachFile(attachfile, "file", 2, false, ref mail);
            }
            mail.Subject = subject;
            //mail以html的格式发送
            mail.IsBodyHtml = true;
            mail.Body = string.Format(@"<table><tr><td><img src=""{0}""/></td></tr><tr><td valign=top style=""height:200px"">" + body + @"</td></tr><tr><td><img src=""{1}""/></td></tr></table>",
                "cid:" + mail.Attachments[0].ContentId, "cid:" + mail.Attachments[1].ContentId);
            var s = new SmtpClient();
            s.Port = 25;
            //邮件服务器地址
            s.Host = "111.111.111.111";
            s.Send(mail);
        }
        //ref 传引用，如对象等都要用这个形式
        //ContentDisposition.Inline用来说明是以内联还是附件的方式发送
        private void attachFile(string attachfile, string cid, int i,bool disattach,ref MailMessage mail)
        {
            Attachment attachFile = new Attachment(attachfile);
            mail.Attachments.Add(attachFile);
            mail.Attachments[i].ContentId = cid;
            mail.Attachments[i].ContentDisposition.Inline = disattach;
            mail.Attachments[i].NameEncoding = mail.SubjectEncoding = mail.BodyEncoding = Encoding.UTF8;
            
        }
    }