发邮件

页面

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!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>
    收件人：<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox><br /><br />
        标题：<asp:TextBox ID="TextBox2" runat="server"></asp:TextBox><br /><br />
        内容：<br />
        <asp:TextBox ID="TextBox3" runat="server" Height="206px" TextMode="MultiLine" Width="248px"></asp:TextBox><br /><br />
        <asp:Button ID="Button1" runat="server" Text="发送" />
    </div>
    </form>
</body>
</html>

后台

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

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        Button1.Click += Button1_Click;//发送按钮

    }
    //发送按钮开始
    void Button1_Click(object sender, EventArgs e)
    {
        //1、引用命名空间using System.Net;  using System.Net.Mail;
        //创建SMTP服务调用类
        SmtpClient smtp = new SmtpClient("smtp.qq.com");
        smtp.EnableSsl = true;
        //发件人
         MailAddress come=new MailAddress("账户");
        //收件人
        MailAddress to=new MailAddress(TextBox1.Text);
        //创建邮件对象
        MailMessage mail=new MailMessage(come,to);
        //邮件对象的内容
        mail.Subject=TextBox2.Text;//邮件标题
        mail.Body=TextBox3.Text;//邮件主体
        //注册证书，验证发件人邮箱密码
        NetworkCredential net = new NetworkCredential("账户", "密码");
        //将证书关联到服务器对象等待验证
        smtp.Credentials = net;
        //调用服务类
        smtp.Send(mail);

    }
    //发送按钮结束
}