In this article I will explain with an example, how to send HTML formatted email using HTML Templates using Mailkit 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 need to be saved in the Web.Config file.
Note: It is necessary to use the sender’s email address credentials while defining the Gmail SMTP Server Credentials as Gmail the sender’s email address must be same as the Gmail Username specified in credentials.
        <smtp deliveryMethod="Network" from="">
                password="GMAILor2STEP-PASSWORD" />

Adding Email Template

The very first step is to Right Click the Project in the Solution Explorer and click Add and then New Item and then select HTML Page and name it as EmailTemplate.htm.
Send Email with HTML Templates using MailKit in ASP.Net MVC

Location of the EmailTemplate

The Email Template is placed inside the Template Folder (Directory) in Project Folder.
Send Email with HTML Templates using MailKit in ASP.Net MVC

Building HTML Template for Email Body

The HTML Template of the Email will be built by generating an HTML containing some placeholders which will be replaced with the actual content.
Advantage of creating templates instead of building HTML using String Builder class or String concatenation in code is that, one can easily change the HTML of the template without changing the code.
The following HTML Email Template consists of four placeholders:
{UserName} – Name of the recipient.
{Url} – Url of the article.
{Title} – Title of the article.
{Description} – Description of the Article.
These placeholders will be replaced with the actual (real) values, when the email is being sent.
<html xmlns="">
    <img style="background:black;" src=""/><br /><br />
    <div style="border-top:3px solid #61028D">&nbsp;</div>
    <span style="font-family:Arial;font-size:10pt">
        Hello <b>{UserName}</b>,<br /><br />
        A new article has been published on ASPSnippets.<br /><br />
        <a style="color:#61028D" href="{Url}">{Title}</a><br />
        <br /><br />
        Thanks<br />

MimeKit MimeMessage and MailKit SmtpClient class

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.


You will need to import the following namespaces.
using System.IO;
using System.Configuration;
using System.Net.Configuration;
using MimeKit;
using MailKit.Net.Smtp;


The Controller consists of the following Action methods.
Action method for handling GET operation
Inside this Action method, simply the View is returned.
Action method for handling POST operation
Inside this Action method, the PopulateBody method is called and title, url, userName and description are passed as parameter to it.
Inside the PopulateBody method, the contents of the HTML Email Template file are read into a String variable using the StreamReader class.
The placeholders are replaced with their respective values and content of the Template is returned as Body.
Then, the values of Host, Port, UserName, Password and Sender email address (from) are fetched from the SMTP section of the Web.Config file and set into the respective properties of the MimeMessage class object.
Setting Body of Email
For Body, an object of Builder class is created. The Body of the email is HTML hence it is set into the HtmlBody property of the Builder class object.
Sending Email
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.
For more details on sending Email using MailKit in MVC, please refer my article Send Email using MailKit in ASP.Net MVC.
public class HomeController : Controller
    // GET: Home
    public ActionResult Index()
        return View();
    public ActionResult SendEmail()
        string userName = "John";
        string title = "ASP.Net MVC Hello World Tutorial with Sample Program example";
        string url = "";
        string description = "Here Mudassar Khan has provided a short Hello World Tutorial using a small Sample Program example on how to use and develop applications in ASP.Net MVC 5 for the first time.";
        string body = this.PopulateBody(userName, title, url, description);
        //Read SMTP section from Web.Config.
        SmtpSection smtpSection = (SmtpSection)ConfigurationManager.GetSection("");
        using (MimeMessage mm = new MimeMessage())
            mm.From.Add(new MailboxAddress("Sender", smtpSection.From));
            mm.To.Add(new MailboxAddress("Recepient", ""));
            mm.Subject = "New article published!";
            BodyBuilder builder = new BodyBuilder();
            builder.HtmlBody = body;
            mm.Body = builder.ToMessageBody();
            using (SmtpClient smtp = new SmtpClient())
                smtp.Connect(smtpSection.Network.Host, smtpSection.Network.Port);
                smtp.Authenticate(smtpSection.Network.UserName, smtpSection.Network.Password);
        ViewBag.Message = "Email sent.";
        return View();
    private string PopulateBody(string userName, string title, string url, string description)
        string body = string.Empty;
        using (StreamReader reader = new StreamReader(Server.MapPath("~/Template/EmailTemplate.htm")))
            body = reader.ReadToEnd();
        body = body.Replace("{UserName}", userName);
        body = body.Replace("{Title}", title);
        body = body.Replace("{Url}", url);
        body = body.Replace("{Description}", description);
        return body;


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 SendEmail.
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 HTML Form, there is Submit Button, which when clicked the form is submitted.
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.
    Layout = null;
<!DOCTYPE html>
    <meta name="viewport" content="width=device-width" />
    @using (Html.BeginForm("SendEmail", "Home", FormMethod.Post))
        <input id="btnSend" type="submit" value="Send" />
    @if (ViewBag.Message != null)
        <script type="text/javascript">
            window.onload = function () {

Possible Errors

The possible errors (exceptions) occurring while sending email with MailKit in .Net are covered in the following article.


Send Email with HTML Templates using MailKit in ASP.Net MVC