public int SendSystem(string email) { Random rnd = new Random(); SmtpServer smtpserver = new SmtpServer("smtp.gmail.com") { Port = 587, ConnectType = SmtpConnectType.ConnectSSLAuto, User = email_login, Password = email_pass }; int code = rnd.Next(100000, 999999); SmtpMail message = new SmtpMail("TryIt") { From = email_login, To = email, Subject = "[Verification Code]", Priority = EASendMail.MailPriority.High }; message.ImportHtmlBody(@"D:\Downloads\mail.html", ImportHtmlBodyOptions.NoOptions); message.HtmlBody = message.HtmlBody.Replace("Your verefication code:", $"Your verefication code:{code}"); Task.Run(() => { SmtpClient client = new SmtpClient(); client.Connect(smtpserver); client.SendMail(message); }); return(code); }