In this article I will explain with an example, how to send email using MailKit library in ASP.Net MVC.
Note: For beginners in ASP.Net MVC, please refer my article ASP.Net MVC Hello World Tutorial with Sample Program example.
 
 
Installing MailKit package
You will need to install the MailKit package, for details on installation please refer Install MailKit from Nuget in Visual Studio.
 
 
Mail Server Settings in Web.Config file
The following Mail Server settings and AppSettings need to be saved in the Web.Config file.
<system.net>
 <mailSettings>
    <smtp deliveryMethod="Network">
      <network
          host="smtp.gmail.com"
          port="587" />
    </smtp>
 </mailSettings>
</system.net>
 
 
CC and BCC in AppSettings section of Web.Config file
The following Mail Server settings and AppSettings need to be saved in the Web.Config file.
<appSettings>
 <add key="Cc" value="cc@aspsnippets.com" />
 <add key="Bcc" value="bcc@aspsnippets.com" />
</appSettings>
 
 
Model
The Model class consists of the following properties.
public class EmailModel
{
    public string To { get; set; }
    public string Subject { get; set; }
    public string Body { get; set; }
    public string Email { get; set; }
    public string Password { get; set; }   
}
 
 
Namespaces
You will need to import the following namespaces.
using MimeKit;
using MailKit.Net.Smtp;
using System.Configuration;
using System.Net.Configuration;
 
 
Controller
The Controller consists of following Action methods.
Action method for handling GET operation
Inside this Action method, simply the View is returned.
 
Action method for handling POST operation
This Action method handles the call made from the POST function from the View.
 
MimeMessage Class Properties
Following are the required properties of the MimeMessage class.
From – Sender’s email address.
To – Recipient(s) Email Address.
CC – Carbon Copies. (If any)
BCC – Blind Carbon Copies. (If any)
Subject – Subject of the Email.
Body – Body of the Email.
Attachments – Attachments. (If any)
ReplyTo – ReplyTo Email address.
 
SmtpClient Class Methods
Following are the methods of the SmtpClient class.
Connect – The connection to the SMTP Server is established using the domain and the port number.
Authenticate – The username and password of the SMTP Server is authenticated.
Send – The MimeMessage object is passed to it and the email is sent.
Disconnect – Disconnects the connection with SMTP Server.
 
When Send button is clicked, the posted values from their respective fields are captured through the EmailModel class object and are passed as parameter to SendEmail function.
Note: For more details on how to use Model class object for capturing Form field values, please refer my article ASP.Net MVC: Form Submit (Post) example.
 
Inside the SendEmail function, all these parameters are set into an object of the MimeMessage class.
The Cc and Bcc addresses are fetched from the AppSettings section of the Web.Config file and are set in the MimeMessage object.
Then, an object of the SmtpClient class is created and the values of Host and Port are fetched from the Smtp section of the Web.Config file and are passed as parameter to the Connect method.
Finally, the methods of the Mail Server such as Connect, Authenticate, Send and Disconnect are executed and a success message is set to a ViewBag object.
public class HomeController : Controller
{
    // GET: Home
    public ActionResult Index()
    {
        return View();
    }
 
    [HttpPost]
    public ActionResult Index(EmailModel model)
    {
        this.SendEmail(model.To, model.Email, model.Password, model.Subject, model.Body);
        ViewBag.Message = "Email sent.";
        return View();
    }
 
    private void SendEmail(string to, string from, string password, string subject, string body)
    {
        //Read SMTP section from Web.Config.
        SmtpSection smtpSection = (SmtpSection)ConfigurationManager.GetSection("system.net/mailSettings/smtp");
        string host = smtpSection.Network.Host;
        int port = smtpSection.Network.Port;
 
        //Read AppSettings section from Web.Config.
        string cc = ConfigurationManager.AppSettings["Cc"];
        string bcc = ConfigurationManager.AppSettings["Bcc"];
 
        using (MimeMessage mm = new MimeMessage())
        {
            mm.From.Add(new MailboxAddress("Sender", from));
            mm.To.Add(new MailboxAddress("Recepient", to));
            mm.Subject = subject;
            mm.Cc.Add(new MailboxAddress("Cc", cc));
            mm.Bcc.Add(new MailboxAddress("Bcc", bcc));
            BodyBuilder builder = new BodyBuilder();
            builder.TextBody = body;
            mm.Body = builder.ToMessageBody();
            using (SmtpClient smtp = new SmtpClient())
            {
                smtp.Connect(host, port);
                smtp.Authenticate(from, password);
                smtp.Send(mm);
                smtp.Disconnect(true);
            }
        }
    }
}
 
 
View
Inside the View, in the very first line the EmailModel class is declared as model for the View.
The View consists of an HTML Form which has been created using the Html.BeginForm method with the following parameters.
ActionName – Name of the Action. In this case the name is Index.
ControllerName – Name of the Controller. In this case the name is Home.
FormMethod – It specifies the Form Method i.e. GET or POST. In this case it will be set to POST.
Inside the Form there is an HTML Table which consists of some TextBoxes created using the Html.TextBoxFor method.
The Table also consists of a TextArea created using Html.TextAreaFor method and a Submit button.
When the Submit Button is clicked, the Form gets submitted and the Model object is sent to the Controller.
Finally, the ViewBag object named Message is checked for NULL and if it is not NULL then the value of the object is displayed using JavaScript Alert Message Box.
@model Send_Email_Mailkit_MVC.Models.EmailModel
@{
    Layout = null;
}
 
<!DOCTYPE html>
 
<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <title>Index</title>
</head>
<body>
    @using (Html.BeginForm("Index", "Home", FormMethod.Post))
    {
        <table border="0" cellpadding="0" cellspacing="0">
            <tr>
                <td style="width: 80px">To:</td>
                <td>@Html.TextBoxFor(model => model.To)</td>
            </tr>
            <tr>
                <td>Subject:</td>
                <td>@Html.TextBoxFor(model => model.Subject)</td>
            </tr>
            <tr>
                <td valign="top">Body:</td>
                <td>@Html.TextAreaFor(model => model.Body, new { rows = "3", cols = "20" })</td>
            </tr>
            <tr>
                <td>Gmail Email:</td>
                <td>@Html.TextBoxFor(model => model.Email)</td>
            </tr>
            <tr>
                <td>Gmail Password:</td>
                <td>@Html.TextBoxFor(model => model.Password, new { type = "password" })</td>
            </tr>
            <tr>
                <td></td>
                <td><input id="btnSend" type="submit" value="Send" /></td>
            </tr>
        </table>
    }
    @if (ViewBag.Message != null)
    {
        <script type="text/javascript">
            window.onload = function () {
                alert("@ViewBag.Message");
            };
        </script>
    }
</body>
</html>
 
 
Possible Errors
The possible errors (exceptions) occurring while sending email with MailKit in .Net are covered in the following article.
Errors (Exceptions) while sending email with MailKit in .Net
 
 
Screenshots
Email Form
Send Email using MailKit in ASP.Net MVC
 
Received Email
Send Email using MailKit in ASP.Net MVC
 
 
Downloads
SendEmail_Mailkit_MVC.zip