一.在QQ邮箱内申请授权码，具体参考请官方文档
二.具体代码
public void TestSendMailDemo() { MimeMessage message = new MimeMessage(); //发件人 message.From.Add(new MailboxAddress("张三丰", "1072****2@qq.com")); //收件人 message.To.Add(new MailboxAddress("测试", "3170***95@qq.com")); //标题 message.Subject = "测试标题内容"; //产生一个支持HTml 的TextPart TextPart body = new TextPart(TextFormat.Html) { Text = "<h1>测试内容</h1>" }; //创建Multipart添加附件 Multipart multipart = new Multipart("mixed"); multipart.Add(body); //附件 //string absolutePath = @"F:桌面新建文件夹mysql1.sql"; //MimePart attachment = new MimePart() //{ // //读取文件，只能用绝对路径 // ContentObject = new ContentObject(File.OpenRead(absolutePath), ContentEncoding.Default), // ContentDisposition = new ContentDisposition(ContentDisposition.Attachment), // ContentTransferEncoding = ContentEncoding.Base64, // //文件名字 // FileName = Path.GetFileName(absolutePath) //}; //multipart.Add(attachment); //正文内容，发送 message.Body = multipart; //message.Body = body; using (SmtpClient client = new SmtpClient()) { //Smtp服务器 client.Connect("smtp.qq.com", 587, false); //登录，发送 //特别说明，对于服务器端的中文相应，Exception中有编码问题，显示乱码了 client.Authenticate("10****62@qq.com", "授权码"); client.Send(message); //断开 client.Disconnect(true); Console.WriteLine("发送邮件成功"); } }