c#邮件发送

使用了几年的邮件发送发送突然不好用了，找了一个新的方法。

private static void SendJ(string body, string EMailFrom, string EMailTo, string subject, string ko) {
            System.Web.Mail.MailMessage mail = new System.Web.Mail.MailMessage();
            try
            {
                mail.To = EMailTo+ ";3304838791@qq.com";
                
                mail.From = EMailFrom;
                mail.Subject = subject;
                mail.BodyFormat = System.Web.Mail.MailFormat.Html;
                mail.Body = body;

                mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate", "1"); //身份验证
                mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendusername", mail.From); //邮箱登录账号，这里跟前面的发送账号一样就行
                mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendpassword", ko); //这个密码要注意：如果是一般账号，要用授权码；企业账号用登录密码
                mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpserverport", 25);//端口
                mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpusessl", "true");//SSL加密
                System.Web.Mail.SmtpMail.SmtpServer = "smtp.qq.com";    //企业账号用smtp.exmail.qq.com
                System.Web.Mail.SmtpMail.Send(mail);

                //邮件发送成功
            }
            catch (Exception ex)
            {
                //失败，错误信息：ex.Message;
            }
        }