Send Email Asynchronously in C#¶

In previous section, I introduced how to use event handler to monitor the progress. In this section, I will introduce how to send email asynchronously in C#.

Sections:

Introduction
[C# - Send Email Asynchronously - Example]
[C# - Send Email with TAP (async, wait) - Example]

Introduction¶

In synchronous mode, once SendMail method is called, it returns to application after the method is complete. Therefore, if the runtime (it depends on the networking connection and the email size) is long, your application cannot do anything before this method ends, which results “my application is blocked or halted”. In contrast, in asynchronous mode, as BeginSendMail method works in background, this methods return to application immediately no matter the running method is complete or not.

Note

Remarks: All of samples in this section are based on first section: Send email in a simple C# project. To compile and run the following example codes successfully, please click here to learn how to create the test project and add reference of EASendMail to your project.

[C# - Send Email Asynchronously - Example]¶

The following example codes demonstrate how to send email asynchronously in C#.

Note

To get the full sample projects, please refer to Samples section.

using System;
using System.Collections.Generic;
using System.Text;
using EASendMail; //add EASendMail namespace
namespace mysendemail
{
    class Program
    {
        static void Main(string[] args)
        {
            try
            {
                SmtpMail oMail = new SmtpMail("TryIt");

                // Set sender email address, please change it to yours
                oMail.From = "test@emailarchitect.net";
                // Set recipient email address, please change it to yours
                oMail.To = "support@emailarchitect.net";

                // Set email subject
                oMail.Subject = "test email from c# with asynchronous mode";
                // Set email body
                oMail.TextBody = "this is a test email sent from c# project with asynchronous mode";

                // Your smtp server address
                SmtpServer oServer = new SmtpServer("smtp.emailarchitect.net");

                // User and password for ESMTP authentication
                oServer.User = "test@emailarchitect.net";
                oServer.Password = "testpassword";

                // Most mordern SMTP servers require SSL/TLS connection now.
                // ConnectTryTLS means if server supports SSL/TLS, SSL/TLS will be used automatically.
                oServer.ConnectType = SmtpConnectType.ConnectTryTLS;

                // If your SMTP server uses 587 port
                // oServer.Port = 587;

                // If your SMTP server requires SSL/TLS connection on 25/587/465 port
                // oServer.Port = 25; // 25 or 587 or 465
                // oServer.ConnectType = SmtpConnectType.ConnectSSLAuto;

                Console.WriteLine("start to send email in asynchronous mode...");

                SmtpClient oSmtp = new SmtpClient();
                SmtpClientAsyncResult oResult = oSmtp.BeginSendMail(
                        oServer, oMail, null, null);
                // Wait for the email sending...
                while (!oResult.IsCompleted)
                {
                    Console.WriteLine("waiting..., you can do other thing!");
                    oResult.AsyncWaitHandle.WaitOne(50, false);
                }
                oSmtp.EndSendMail(oResult);

                Console.WriteLine("email was sent successfully!");
            }
            catch (Exception ep)
            {
                Console.WriteLine("failed to send email with the following error:");
                Console.WriteLine(ep.Message);
            }
        }
    }
}

[C# - Send Email with TAP (async, wait) - Example]¶

SmtpClient also supports task asynchronous programming model (TAP), you can use async and await to send email asynchronously.

using System;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using EASendMail; //add EASendMail namespace

namespace mysendemail
{
    class Program
    {
        static async Task Main(string[] args)
        {
            try
            {
                SmtpMail oMail = new SmtpMail("TryIt");

                // Set sender email address, please change it to yours
                oMail.From = "test@emailarchitect.net";
                // Set recipient email address, please change it to yours
                oMail.To = "support@emailarchitect.net";

                // Set email subject
                oMail.Subject = "test email from c# with asynchronous mode";
                // Set email body
                oMail.TextBody = "this is a test email sent from c# project with asynchronous mode";

                // Your smtp server address
                SmtpServer oServer = new SmtpServer("smtp.emailarchitect.net");

                // User and password for ESMTP authentication
                oServer.User = "test@emailarchitect.net";
                oServer.Password = "testpassword";

                // Most mordern SMTP servers require SSL/TLS connection now.
                // ConnectTryTLS means if server supports SSL/TLS, SSL/TLS will be used automatically.
                oServer.ConnectType = SmtpConnectType.ConnectTryTLS;

                // If your SMTP server uses 587 port
                // oServer.Port = 587;

                // If your SMTP server requires SSL/TLS connection on 25/587/465 port
                // oServer.Port = 25; // 25 or 587 or 465
                // oServer.ConnectType = SmtpConnectType.ConnectSSLAuto;

                Console.WriteLine("start to send email in asynchronous mode...");

                SmtpClient oSmtp = new SmtpClient();
                await oSmtp.SendMailAsync(oServer, oMail);

                Console.WriteLine("email was sent successfully!");
            }
            catch (Exception ep)
            {
                Console.WriteLine("failed to send email with the following error:");
                Console.WriteLine(ep.Message);
            }
        }
    }
}

Next Section

At next section I will introduce how to send mass emails with multiple threads in C#.

Tutorial Index

Send Email Asynchronously in C#¶

Introduction¶

[C# - Send Email Asynchronously - Example]¶

[C# - Send Email with TAP (async, wait) - Example]¶

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