Send Email using Gmail in C#

In previous section, I introduced how to send email over SSL/TLS connection. In this section, I will introduce how to send email using Gmail account in C#.

Introduction

Gmail SMTP server address is smtp.gmail.com. It requires implicit SSL or explicit SSL (TLS) connection, and you should use your Gmail email address as the user name for ESMTP authentication.

For example: your email is gmailid@gmail.com, and then the user name should be gmailid@gmail.com.

Server Port SSL/TLS
smtp.gmail.com 25, 587 TLS
smtp.gmail.com 465 SSL

Important

If you got authentication error, you need to enable Allowing less secure apps or Sign in using App Passwords.

Another way is Gmail OAUH, please see Gmail SMTP OAUTH section.

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 using Gmail Account over Implicit SSL on 465 Port]

The following example codes demonstrate how to send email using Gmail account over SSL 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)
        {
            SmtpMail oMail = new SmtpMail("TryIt");
            SmtpClient oSmtp = new SmtpClient();

            // Your gmail email address
            oMail.From = "gmailid@gmail.com";

            // Set recipient email address
            oMail.To = "support@emailarchitect.net";

            // Set email subject
            oMail.Subject = "test email from gmail account";

            // Set email body
            oMail.TextBody = "this is a test email sent from c# project with gmail.";
            // Gmail SMTP server address
            SmtpServer oServer = new SmtpServer("smtp.gmail.com");

            // Set 465 port
            oServer.Port = 465;

            // detect SSL/TLS automatically
            oServer.ConnectType = SmtpConnectType.ConnectSSLAuto;

            // Gmail user authentication
            // For example: your email is "gmailid@gmail.com", then the user should be the same
            oServer.User = "gmailid@gmail.com";
            oServer.Password = "yourpassword";

            try
            {
                Console.WriteLine("start to send email over SSL ...");
                oSmtp.SendMail(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);
            }
        }
    }
}

[C# - Send Email using Gmail Account over Explicit SSL (TLS) on 25 or 587 Port]

The following example codes demonstrate how to send email using Gmail account over TLS 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)
        {
            SmtpMail oMail = new SmtpMail("TryIt");
            SmtpClient oSmtp = new SmtpClient();

            // Your gmail email address
            oMail.From = "gmailid@gmail.com";

            // Set recipient email address
            oMail.To = "support@emailarchitect.net";

            // Set email subject
            oMail.Subject = "test email from gmail account";

            // Set email body
            oMail.TextBody = "this is a test email sent from c# project with gmail.";
            // Gmail SMTP server address
            SmtpServer oServer = new SmtpServer("smtp.gmail.com");

            // Set 587 port, if you want to use 25 port, please change 587 5o 25
            oServer.Port = 587;

            // detect SSL/TLS automatically
            oServer.ConnectType = SmtpConnectType.ConnectSSLAuto;

            // Gmail user authentication
            // For example: your email is "gmailid@gmail.com", then the user should be the same
            oServer.User = "gmailid@gmail.com";
            oServer.Password = "yourpassword";
            try
            {
                Console.WriteLine("start to send email over SSL ...");
                oSmtp.SendMail(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);
            }
        }
    }
}

Gmail SMTP OAUTH

The Gmail IMAP and SMTP servers have been extended to support authorization via the industry-standard OAuth 2.0 protocol. Using OAUTH protocol, user can do authentication by Gmail Web OAuth instead of inputting user and password directly in application. This way is more secure, but a little bit complex.

Using Gmail SMTP OAUTH

Next Section

At next section I will introduce how to send email using Yahoo account in C#.

Appendix

Comments

If you have any comments or questions about above example codes, please click here to add your comments.