Not able to send SMTP email using 2 factore authentication using passkey in ASP.NET MVC

try
            {
                host = ConfigurationManager.AppSettings["SMTPHost"];
                port = ConfigurationManager.AppSettings["SMTPPort"];
                sender = ConfigurationManager.AppSettings["SenderEmail"];
                password = ConfigurationManager.AppSettings["SenderPwd"];

                using (MailMessage mailMsg = new MailMessage())
                {
                    mailMsg.From = new MailAddress(sender);
                    mailMsg.To.Add(inputInfo.Recipient);
                    if (!string.IsNullOrEmpty(inputInfo.RecipientCC))
                    {
                        //if (inputInfo.CommID==(int)CommunicationID.CLAIM_Opted_INSTANTMONY_REJECT_EMAIL || inputInfo.CommID==(int)CommunicationID.CLAIM_ReInspection)
                        //{
                        //    inputInfo.RecipientCC = "";
                        //       inputInfo.RecipientCC =  ConfigurationManager.AppSettings["ZCH"] + "," + ConfigurationManager.AppSettings["SCH"];
                        //}
                        mailMsg.CC.Add(inputInfo.RecipientCC);
                    }

                    mailMsg.Subject = inputInfo.Subject;
                    mailMsg.Body = inputInfo.CommText;
                    mailMsg.IsBodyHtml = true;

                    using (SmtpClient smtp = new SmtpClient(host, Convert.ToInt32(port)))
                    {
                        smtp.UseDefaultCredentials = false;
                        smtp.Credentials = new NetworkCredential(sender, password);
                        smtp.EnableSsl = true;
                        smtp.Send(mailMsg);
                    }
                }
            }

Web.config

<add key="SenderPwd" value="passkey" />


not able to send mail using SMTP 2 factor authentication in asp.net mvc

The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.57 Client not authenticated to send mail. Error: 535 5.7.139 Authentication unsuccessful