asp.net带附件功能的简单发送邮件

<div> 

    收件人：<asp:TextBox ID="txt_toman" runat="server"></asp:TextBox> 

        <br /> 

        主题：<asp:TextBox ID="txt_title" runat="server"></asp:TextBox> 

        <br /> 

        内容：<asp:TextBox ID="txt_content" runat="server" Height="66px"  

            TextMode="MultiLine" Width="194px"></asp:TextBox> 

        <br /> 

        附件：<asp:FileUpload ID="FileUpload1" runat="server" /> 

        <br /> 

        <asp:Button ID="btn_send" runat="server" onclick="btn_send_Click"  

            Text="   Send   " /> 

        <asp:Label ID="lbl_mag" runat="server" ForeColor="Red"></asp:Label> 

    </div> 

view plain

using System; 

using System.Collections.Generic; 

using System.Linq; 

using System.Web; 

using System.Web.UI; 

using System.Web.UI.WebControls; 

using System.Net.Mail; 

using System.Text; 

namespace WebApplication1 

{ 

    public partial class WebForm1 : System.Web.UI.Page 

    { 

        protected void Page_Load(object sender, EventArgs e) 

        { 

        } 

        protected void btn_send_Click(object sender, EventArgs e) 

        { 

            bool flag = SendMail("发信人地址", "发信人", "用户名", "密码", txt_title.Text, txt_content.Text, txt_toman.Text, FileUpload1); 

            if (flag) 

            { 

                lbl_mag.Text = "发送成功"; 

            } 

            else 

            { 

                lbl_mag.Text = "糟糕，发送失败啦！"; 

            } 

        } 

        /// <summary> 

        /// 简单邮件发送器 

        /// </summary> 

        /// <param name="user">发信人地址</param> 

      &