// 1.创建邮件

MailMessage mailMsg = new MailMessage();

mailMsg.To.Add(new MailAddress("test@test.com"));

// 2.设置邮件标题、正文等信息

mailMsg.HeadersEncoding = Encoding.GetEncoding("gb2312");

mailMsg.SubjectEncoding = Encoding.GetEncoding("gb2312");

mailMsg.BodyEncoding = Encoding.GetEncoding("gb2312"); // 邮件内容编码

mailMsg.Subject = emailTitleStr; // 邮件标题

mailMsg.Body = emailBodyStr;

mailMsg.IsBodyHtml = true; // 邮件内容是否支持html

mailMsg.Priority = MailPriority.High;

// 附件：在 .net 4.0中，附件名称含有特殊名称时，接收方将收到名字为空的附件

mailMsg.Attachments.Add(new Attachment("D:\资料(2016).txt"));

// 3.创建SMTP发送

SmtpClient smtp = new SmtpClient(emailSMTP, emailPort);

smtp.Credentials = new NetworkCredential(emailName.Address, emailPwd);

smtp.DeliveryMethod = SmtpDeliveryMethod.Network;

smtp.Send(mailMsg);