c# 发邮件

 public class EmailHelper
    {
        public static void SendMail(string from, string to, string subject, string body, string attachmentFilePath)
        {
            MailMessage message = new MailMessage();
            message.From = new MailAddress(from);
            message.To.Add(new MailAddress(to));
            message.Subject = subject;
            message.Body = body;
            message.Attachments.Add(new Attachment(attachmentFilePath));

            SmtpClient smtp = new SmtpClient();
　　　　　　　//不同的邮箱的smtp服务器地址都是不同的，如qq的是smtp.qq.com
            smtp.Host = "smtp.163.com";
           
            smtp.Port = 25;
            smtp.Credentials = new System.Net.NetworkCredential("邮箱账号（发送邮箱）", "密码");
           
            smtp.Send(message);
        }
    }

 EmailHelper.SendMail("邮箱账号（发送邮箱）", "邮箱账号（接收邮箱）", "标题", "内容", "附件地址，没有就null");