電子郵件不會發送給大量的人

Question

我有以下代碼發送電子郵件提醒約60個用戶提取上傳時。如果我在本地運行它，它會發送給所有帳戶，但是當我將其上傳到服務器時，它不會發送任何電子郵件，除非它僅限於一個人。我沒有太多經驗與託管和服務器的東西，所以任何幫助，你可以給我會很好。

   if (Session["ExtractNo"].ToString() == "Extract 1") 
      { 

       //Connection String (SendEmail) 
       string SendEmail = ConfigurationManager.ConnectionStrings["Sendmail"].ConnectionString; 

       SqlDataReader reader; 
       String SendMessage = "SELECT Name, Position, Email FROM AuthorisedStaff Where Position = 'CM' or Position = 'DHOD' or Position = 'HOD'"; //<---- change position before launch 

       using (SqlConnection myConnection = new SqlConnection(SendEmail)) 
       { 
        myConnection.Open(); 
        SqlCommand myCommand = new SqlCommand(SendMessage, myConnection); 

        ArrayList emailArray = new ArrayList(); 
        reader = myCommand.ExecuteReader(); 

        var emails = new List<EmailCode>(); 

        while (reader.Read()) 
        { 
         emails.Add(new EmailCode 
         { 
          Email = Convert.ToString(reader["Email"]), 
          Name = Convert.ToString(reader["Name"]), 
          Position = Convert.ToString(reader["Position"]) 
         }); 
        } 

        foreach (EmailCode email in emails) 
        { 
         //Email Config 

         const string username = "roll@test.ac.uk"; //account address 
         const string password = "######"; //account password 

         SmtpClient smtpclient = new SmtpClient(); 
         MailMessage mail = new MailMessage(); 
         MailAddress fromaddress = new MailAddress("roll@test.ac.uk", "PTLP"); //address and from name 

         smtpclient.Host = "omavex011"; //host name for particular email address 
         smtpclient.Port = 25; //port number for particular email address 

         mail.From = fromaddress; 
         mail.To.Add(email.Email); 
         mail.Subject = ("PTLP Check"); 

         mail.IsBodyHtml = true; 

         //change context of message below as appropriate 
         mail.Body = HttpUtility.HtmlEncode(email.Name) + " <br /> <p>Part Time Payroll details are now available for checking.</p> "; 

         //smtpclient.EnableSsl = true; 
         smtpclient.DeliveryMethod = SmtpDeliveryMethod.Network; 
         smtpclient.Credentials = new System.Net.NetworkCredential(username, password); 

         smtpclient.Send(mail); 

        } 
       } 

      } 

Answer 1

正如我在評論中提及了這是你將如何使用一個SmtpClient實例：

 if (Session["ExtractNo"].ToString() == "Extract 1") 
     { 
      //Email Config 
      const string username = "roll@test.ac.uk"; //account address 
      const string password = "######"; //account password 

      SmtpClient smtpclient = new SmtpClient(); 
      smtpclient.Host = "omavex011"; 
      smtpclient.Port = 25; 
      smtpclient.DeliveryMethod = SmtpDeliveryMethod.Network; 
      smtpclient.Credentials = new System.Net.NetworkCredential(username, password); 

      string SendEmail = ConfigurationManager.ConnectionStrings["Sendmail"].ConnectionString; 

      SqlDataReader reader; 
      String SendMessage = "SELECT Name, Position, Email FROM AuthorisedStaff Where Position = 'CM' or Position = 'DHOD' or Position = 'HOD'"; //<---- change position before launch 

      using (SqlConnection myConnection = new SqlConnection(SendEmail)) 
      { 
       myConnection.Open(); 
       SqlCommand myCommand = new SqlCommand(SendMessage, myConnection); 

       ArrayList emailArray = new ArrayList(); 
       reader = myCommand.ExecuteReader(); 

       var emails = new List<EmailCode>(); 

       while (reader.Read()) 
       { 
        emails.Add(new EmailCode { Email = Convert.ToString(reader["Email"]), 
              Name = Convert.ToString(reader["Name"]), 
              Position = Convert.ToString(reader["Position"]) 
              }); 
              } 

       foreach (EmailCode email in emails) 
       { 

        MailMessage mail = new MailMessage(); 
        MailAddress fromaddress = new MailAddress("roll@test.ac.uk", "PTLP"); //address and from name 

        mail.From = fromaddress; 
        mail.To.Add(email.Email); 
        mail.Subject = ("PTLP Check"); 
        mail.IsBodyHtml = true; 
        mail.Body = HttpUtility.HtmlEncode(email.Name) + " <br /> <p>Part Time Payroll details are now available for checking.</p> "; 
        smtpclient.Send(mail); 
       } 
      } 
      smtpclient.Dispose(); 
      }