1.安装jmail4.3

2.找到jmail.dll（Program Files\Dimac\w3JMail4下）

3.执行Program Files\Microsoft Visual Studio .NET\FrameworkSDK\Bin\ildasm.exe（可使用Visual Studio .Net 2003 命令提示),

格式如下：tlbimp c:\Program Files\Dimac\w3JMail4\jmail.dll /out:myJmail.dll /namespace:myJmail

就是我在Visual Studio .Net 2005命令提示下编译执行 tlbimp c:\Program Files\Dimac\w3JMail4\jmail.dll /out:myJmail.dll /namespace:myJmail
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.Web.Mail;
using System.Web.Util;
using myJmail;

using Tool;
using Manager;
using Entity;

public partial class UserControls_Jmaill : System.Web.UI.UserControl
{
    string strCurrentPath = DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString();
    protected void Page_Load(object sender, EventArgs e)
    {
    }
    protected void btnSend_Click(object sender, EventArgs e)
    {
        try
        {
            this.lblTitle.Text = "发送邮件控件";
 
            myJmail.Message Jmail = new myJmail.Message();
            DateTime t = DateTime.Now;
            String Subject = this.txtTitle.Text;
            String body = this.txtContent.Text;
            string FromEmail = this.txtFormEmail.Text.Trim();//你的email
            String ToEmail = this.txtToEmail.Text;//对方的email
            String AddAttachment = this.FileUploadSubject.PostedFile.FileName;
            //Silent属性：如果设置为true,JMail不会抛出例外错误. JMail. Send( () 会根据操作结果返回true或false
            Jmail.Silent = true;
            //Jmail创建的日志，前提loging属性设置为true
            Jmail.Logging = true;
            //字符集，缺省为"US-ASCII"
            Jmail.Charset = "GB2312";
            //信件的contentype. 缺省是"text/plain"） : 字符串如果你以HTML格式发送邮件, 改为"text/html"即可。
          //  Jmail.ContentType = "text/html";
            ToEmail = ToEmail.Replace("\n", "").Replace(" ", "");
            string[] str = ToEmail.Split(’,’);

            for (int i = 0; i < str.Length; i++)
            {
                //添加收件人
                Jmail.AddRecipient(str[i], "", "");
               
                Jmail.From = FromEmail;
                //发件人邮件用户名
                Jmail.MailServerUserName = FromEmail;
                //发件人邮件密码
                Jmail.MailServerPassWord = "";//FromEmail邮箱的登陆密码
                //设置邮件标题
                Jmail.Subject = Subject;
                //邮件添加附件,(多附件的话，可以再加一条Jmail.AddAttachment( "c:\\test.jpg",true,null);)就可以搞定了。［注］：加了附件，讲把上面的Jmail.ContentType="text/html";删掉。否则会在邮件里出现乱码。
                Jmail.AddAttachment(AddAttachment, true, null);
                //邮件内容
                Jmail.Body = body + t.ToString();
                //加密文件
                //Jmail.PGPEncrypt = true;
                //Jmail发送的方法
                Jmail.Send("smtp.163.com", false);
                Jmail.ClearAttachments();
                Jmail.ClearRecipients();
            }
            Jmail.Close();
        }
        catch (Exception ex)
        {
            this.lblMessage.Text = ex.Message;
        }
    }
 
}