Sending E-mail using C#

Question

I need to send email via my C# app.

I come from a VB 6 background and had a lot of bad experiences with the MAPI control. First of all, MAPI did not support HTML emails and second, all the emails were sent to my default mail outbox. So I still needed to click on send receive.

If I needed to send bulk html bodied emails (100 - 200), what would be the best way to do this in C#?

Thanks in advance.

Answer 1

The best way to send bulk emails for more faster way is to use threads.I have written this console application for sending bulk emails.I have seperated the bulk email ID into two batches by creating two thread pools.

using System;
using System.Collections.Generic;
using System.Text;
using System.Threading;
using System.Net.Mail;

namespace ConsoleApplication1
{
    public class SendMail 
    {
        string[] NameArray = new string[10] { "Recipient 1", 
                                              "Recipient 2",
                                              "Recipient 3",
                                              "Recipient 4", 
                                              "Recipient 5", 
                                              "Recipient 6", 
                                              "Recipient 7", 
                                              "Recipient 8",
                                              "Recipient 9",
                                              "Recipient 10"
                                            };        

        public SendMail(int i, ManualResetEvent doneEvent)
        {
            Console.WriteLine("Started sending mail process for {0} - ", NameArray[i].ToString() + " at " + System.DateTime.Now.ToString());
            Console.WriteLine("");
            SmtpClient mailClient = new SmtpClient();
            mailClient.Host = Your host name;
            mailClient.UseDefaultCredentials = true;
            mailClient.Port = Your mail server port number; // try with default port no.25

            MailMessage mailMessage = new MailMessage(FromAddress,ToAddress);//replace the address value
            mailMessage.Subject = "Testing Bulk mail application";
            mailMessage.Body = NameArray[i].ToString();
            mailMessage.IsBodyHtml = true;
            mailClient.Send(mailMessage);
            Console.WriteLine("Mail Sent succesfully for {0} - ",NameArray[i].ToString() + " at " + System.DateTime.Now.ToString());
            Console.WriteLine("");

            _doneEvent = doneEvent;
        }

        public void ThreadPoolCallback(Object threadContext)
        {
            int threadIndex = (int)threadContext;
            Console.WriteLine("Thread process completed for {0} ...",threadIndex.ToString() + "at" +  System.DateTime.Now.ToString());
            _doneEvent.Set();
        }      

        private ManualResetEvent _doneEvent;
    }


    public class Program
    {
        static int TotalMailCount, Mailcount, AddCount, Counter, i, AssignI;  
        static void Main(string[] args)
        {
            TotalMailCount = 10;
            Mailcount = TotalMailCount / 2;
            AddCount = Mailcount;
            InitiateThreads();                     

            Thread.Sleep(100000);
        }

       static void InitiateThreads()
       {
            //One event is used for sending mails for each person email id as batch
           ManualResetEvent[] doneEvents = new ManualResetEvent[Mailcount];

            // Configure and launch threads using ThreadPool:
            Console.WriteLine("Launching thread Pool tasks...");

            for (i = AssignI; i < Mailcount; i++)            
            {
                doneEvents[i] = new ManualResetEvent(false);
                SendMail SRM_mail = new SendMail(i, doneEvents[i]);
                ThreadPool.QueueUserWorkItem(SRM_mail.ThreadPoolCallback, i);
            }

            Thread.Sleep(10000);

            // Wait for all threads in pool to calculation...
            //try
            //{
            // //   WaitHandle.WaitAll(doneEvents);
            //}
            //catch(Exception e)
            //{
            //    Console.WriteLine(e.ToString());   
            //}

            Console.WriteLine("All mails are sent in this thread pool.");
            Counter = Counter+1;
            Console.WriteLine("Please wait while we check for the next thread pool queue");
            Thread.Sleep(5000);
            CheckBatchMailProcess();            
        }

        static  void CheckBatchMailProcess()
        {

            if (Counter < 2)
            {
                Mailcount = Mailcount + AddCount;
                AssignI = Mailcount - AddCount;
                Console.WriteLine("Starting the Next thread Pool");

                Thread.Sleep(5000);
                InitiateThreads();
            }

            else
            {
                Console.WriteLine("No thread pools to start - exiting the batch mail application");
                Thread.Sleep(1000);
                Environment.Exit(0);
            }
        }
    }   
}

I have defined 10 recepients in the array list for a sample.It will create two batches of emails to create two thread pools to send mails.You can pick the details from your database also.

You can use this code by copying and pasting it in a console application.(Replacing the program.cs file).Then the application is ready to use.

I hope this helps you :).

Answer 2

Let's make something as a full solution :). Maybe it can help as well. It is a solution for sending one email content and one attach file (or without attach) to many Email addresses. Of course sending just one email is possibility as well. Result is List object with data what is OK and what is not.

namespace SmtpSendingEmialMessage
{ 
    public class EmailSetupData
    {
        public string EmailFrom { get; set; }
        public string EmailUserName { get; set; }
        public string EmailPassword { get; set; }
        public string EmailSmtpServerName { get; set; }
        public int EmailSmtpPortNumber { get; set; }
        public Boolean SSLActive { get; set; } = false;
    }

    public class SendingResultData
    {
        public string SendingEmailAddress { get; set; }
        public string SendingEmailSubject { get; set; }
        public DateTime SendingDateTime { get; set; }
        public Boolean SendingEmailSuccess { get; set; }
        public string SendingEmailMessage { get; set; }
    }
    public class OneRecData
    {
        public string RecEmailAddress { get; set; } = "";
        public string RecEmailSubject { get; set; } = "";
    }


    public class SendingProcess
    {
        public string EmailCommonSubjectOptional { get; set; } = "";
        private EmailSetupData EmailSetupParam { get; set; }
        private List<OneRecData> RecDataList { get; set; }
        private string EmailBodyContent { get; set; }
        private Boolean IsEmailBodyHtml { get; set; }
        private string EmailAttachFilePath { get; set; }

        public SendingProcess(List<OneRecData> MyRecDataList, String MyEmailTextContent, String MyEmailAttachFilePath, EmailSetupData MyEmailSetupParam, Boolean EmailBodyHtml)
        {
            RecDataList = MyRecDataList;
            EmailBodyContent = MyEmailTextContent;
            EmailAttachFilePath = MyEmailAttachFilePath;
            EmailSetupParam = MyEmailSetupParam;
            IsEmailBodyHtml = EmailBodyHtml;
        }

        public List<SendingResultData> SendAll()
        {
            List<SendingResultData> MyResList = new List<SendingResultData>();
            foreach (var js in RecDataList)
            {
                using (System.Net.Mail.MailMessage MyMes = new System.Net.Mail.MailMessage())
                {
                    DateTime SadaJe = DateTime.Now;
                    Boolean IsOK = true;
                    String MySendingResultMessage = "Sending OK";

                    String MessageSubject = EmailCommonSubjectOptional;
                    if (MessageSubject == "")
                    {
                        MessageSubject = js.RecEmailSubject;
                    }

                    try
                    {

                        System.Net.Mail.MailAddress MySenderAdd = new System.Net.Mail.MailAddress(js.RecEmailAddress);
                        MyMes.To.Add(MySenderAdd);
                        MyMes.Subject = MessageSubject;
                        MyMes.Body = EmailBodyContent;
                        MyMes.Sender = new System.Net.Mail.MailAddress(EmailSetupParam.EmailFrom);
                        MyMes.ReplyToList.Add(MySenderAdd);
                        MyMes.IsBodyHtml = IsEmailBodyHtml;

                    }
                    catch(Exception ex)
                    {
                        IsOK = false;
                        MySendingResultMessage ="Sender or receiver Email address error." +  ex.Message;
                    }

                    if (IsOK == true)
                    {
                        try
                        {
                            if (EmailAttachFilePath != null)
                            {
                                if (EmailAttachFilePath.Length > 5)
                                {
                                    MyMes.Attachments.Add(new System.Net.Mail.Attachment(EmailAttachFilePath));
                                }
                            }
                        }
                        catch (Exception ex)
                        {
                            IsOK = false;
                            MySendingResultMessage ="Emial attach error. " +  ex.Message;
                        }

                        if (IsOK == true)
                        {
                            using (System.Net.Mail.SmtpClient MyCl = new System.Net.Mail.SmtpClient())
                            {
                                MyCl.EnableSsl = EmailSetupParam.SSLActive;
                                MyCl.Host = EmailSetupParam.EmailSmtpServerName;
                                MyCl.Port = EmailSetupParam.EmailSmtpPortNumber;
                                try
                                {
                                    MyCl.Credentials = new System.Net.NetworkCredential(EmailSetupParam.EmailUserName, EmailSetupParam.EmailPassword);
                                }
                                catch (Exception ex)
                                {
                                    IsOK = false;
                                    MySendingResultMessage = "Emial credential error. " + ex.Message;
                                }

                                if (IsOK == true)
                                {
                                    try
                                    {
                                        MyCl.Send(MyMes);
                                    }
                                    catch (Exception ex)
                                    {
                                        IsOK = false;
                                        MySendingResultMessage = "Emial sending error. " + ex.Message;
                                    }
                                }
                            }
                        }
                    }

                    MyResList.Add(new SendingResultData
                    {
                            SendingDateTime = SadaJe,
                            SendingEmailAddress = js.RecEmailAddress,
                            SendingEmailMessage = MySendingResultMessage,
                            SendingEmailSubject = js.RecEmailSubject,
                            SendingEmailSuccess = IsOK
                    });
                }

            }
            return MyResList;
        }
    }

}

Answer 3

I can strongly recommend the aspNetEmail library: http://www.aspnetemail.com/

The System.Net.Mail will get you somewhere if your needs are only basic, but if you run into trouble, please check out aspNetEmail. It has saved me a bunch of time, and I know of other develoeprs who also swear by it!

Answer 4

You could use the System.Net.Mail.MailMessage class of the .NET framework.

You can find the MSDN documentation here.

Here is a simple example (code snippet):

using System.Net;
using System.Net.Mail;
using System.Net.Mime;

...
try
{

   SmtpClient mySmtpClient = new SmtpClient("my.smtp.exampleserver.net");

    // set smtp-client with basicAuthentication
    mySmtpClient.UseDefaultCredentials = false;
   System.Net.NetworkCredential basicAuthenticationInfo = new
      System.Net.NetworkCredential("username", "password");
   mySmtpClient.Credentials = basicAuthenticationInfo;

   // add from,to mailaddresses
   MailAddress from = new MailAddress("[e-mail]", "TestFromName");
   MailAddress to = new MailAddress("[e-mail]", "TestToName");
   MailMessage myMail = new System.Net.Mail.MailMessage(from, to);

   // add ReplyTo
   MailAddress replyto = new MailAddress("[e-mail]");
   myMail.ReplyToList.Add(replyTo);

   // set subject and encoding
   myMail.Subject = "Test message";
   myMail.SubjectEncoding = System.Text.Encoding.UTF8;

   // set body-message and encoding
   myMail.Body = "<b>Test Mail</b><br>using <b>HTML</b>.";
   myMail.BodyEncoding = System.Text.Encoding.UTF8;
   // text or html
   myMail.IsBodyHtml = true;

   mySmtpClient.Send(myMail);
}

catch (SmtpException ex)
{
  throw new ApplicationException
    ("SmtpException has occured: " + ex.Message);
}
catch (Exception ex)
{
   throw ex;
}

Answer 5

You can send email using SMTP or CDO

using SMTP:

mail.From = new MailAddress("[e-mail]");
mail.To.Add("to_address");
mail.Subject = "Test Mail";
mail.Body = "This is for testing SMTP mail from GMAIL";

SmtpServer.Port = 587;
SmtpServer.Credentials = new System.Net.NetworkCredential("username", "password");
SmtpServer.EnableSsl = true;

source : C# SMTP Email

CDO.Message oMsg = new CDO.Message();
CDO.IConfiguration iConfg;
iConfg = oMsg.Configuration;
ADODB.Fields oFields;
oFields = iConfg.Fields;
ADODB.Field oField = oFields["http://schemas.microsoft.com/cdo/configuration/sendusing"];
oFields.Update();
oMsg.Subject = "Test CDO";
oMsg.From = "from_address";
oMsg.To = "to_address";
oMsg.TextBody = "CDO Mail test";
oMsg.Send();

Source: C# CDO Email

Manly

Answer 6

Use the namespace System.Net.Mail. Here is a link to the MSDN page

You can send emails using SmtpClient class.

I paraphrased the code sample, so checkout MSDNfor details.

MailMessage message = new MailMessage(
   "[e-mail]",
   "[e-mail]",
   "Subject goes here",
   "Body goes here");

SmtpClient client = new SmtpClient(server);
client.Send(message);

The best way to send many emails would be to put something like this in forloop and send away!