asp.net使用qq邮箱发送邮件

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Mail;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace WebApplication1
{
    public partial class Cemail : System.Web.UI.Page
    {
        private string sfrom = "111111@qq.com";//发送人邮箱
        private string sfromer = "发送人";
        private string stoer = "收件人";
        private string sSMTPHost = "smtp.qq.com";//SMTP服务器
        private string sSMTPuser = "111111@qq.com";//用户登录名
        private string sSMTPpass = "授权码";//登陆密码-新版之后的QQ邮箱都是使用授权码,需要到邮箱-设置-账户里面找到-生成授权码-复制进来;
        protected void Page_Load(object sender, EventArgs e)
        {

        }

        protected void btnSend_Click(object sender, EventArgs e)
        {
            string sto = txtSto.Text.Trim();
            string cc = txtCC.Text.Trim();
            string title = txtTitle.Text.Trim();
            string content = txtContent.Text.Trim();
            if (string.IsNullOrEmpty(sto) || string.IsNullOrEmpty(title) || string.IsNullOrEmpty(content))
            {
                Response.Write("<script>alert('收件人，标题，内容不能为空')</script>");
            }
            else
            {
                MailAddress from = new MailAddress(sfrom, sfromer);//发件人地址对象
                MailAddress to = new MailAddress(sto, stoer);//收件人地址对象
                MailMessage oMail = new MailMessage(from, to);
                oMail.Subject = title;//设置邮件标题
                oMail.Body = content;//设置邮件文本内容
                oMail.IsBodyHtml = false;//设置为HTML格式
                oMail.BodyEncoding = System.Text.Encoding.GetEncoding("GB2312");//正文编码
                oMail.Priority = MailPriority.High;//优先级
                if (cc != "")
                {
                    if (cc.ToLower().IndexOf(';') > 0)
                    {
                        cc = cc.Substring(0, cc.Length - 1);
                        string[] acc = cc.Split(';');
                        foreach (var c in acc)
                        {
                            oMail.CC.Add(c);
                        }
                    }
                    else
                    {
                        oMail.CC.Add(cc);
                    }
                }
                SmtpClient client=new SmtpClient();
                client.EnableSsl = true;//由于使用了授权码必须设置该属性为true
                client.Host = sSMTPHost;//指定SMTP服务器
                client.Credentials = new NetworkCredential(sSMTPuser, sSMTPpass);//邮箱的用户名和密码，注意使用qq邮箱时密码使用的是授权码
                client.DeliveryMethod = SmtpDeliveryMethod.Network;//指定电子邮件发送方式
                try
                {
                    client.Send(oMail);
                    Response.Write("<script>alert('发送成功')</script>");
                }
                catch
                {
                    Response.Write("<script>alert('发送失败')</script>");
                }
                finally
                {
                    oMail.Dispose();
                }
            }           
        }
    }
}

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Cemail.aspx.cs" Inherits="WebApplication1.Cemail" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
        <div>
            <table>
                <tr>
                    <td>收件人邮箱</td>
                    <td>
                        <asp:TextBox ID="txtSto" runat="server"></asp:TextBox></td>
                </tr>
                <tr>
                    <td>抄送</td>
                    <td>
                        <asp:TextBox ID="txtCC" runat="server"></asp:TextBox>
                    </td>
                </tr>
                <tr>
                    <td>标题</td>
                    <td>
                        <asp:TextBox ID="txtTitle" runat="server"></asp:TextBox></td>
                </tr>
                <tr>
                    <td>内容</td>
                    <td>
                        <asp:TextBox ID="txtContent" runat="server" Height="136px" TextMode="MultiLine" Width="254px"></asp:TextBox></td>
                </tr>
                <tr>
                    <td>
                        <asp:Button ID="Button1" runat="server" Text="重置" /></td>

                    <td>
                        <asp:Button ID="btnSend" runat="server" Text="提交" OnClick="btnSend_Click" /></td>
                </tr>
            </table>
        </div>
    </form>
</body>
</html>

qq邮箱设置教程