In this article I will explain with an example, how to send email with Cc and Bcc using MailKit library in ASP.Net Core MVC.
Note: For beginners in ASP.Net Core 7, please refer my article ASP.Net Core 7: 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 AppSettings.json file

The Mail Server settings are saved in the SMTP section as shown below.
{
 "Smtp": {
    "Server": "smtp.gmail.com",
    "Port": 587,
    "CcAddress": "cc@aspsnippets.com",
    "BccAddress": "bcc@aspsnippets.com"
  }
}
 
 

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.
 
 

Model

The Model class consists of the following properties.
public class EmailModel
{
    public string To { getset; }
    public string Subject { getset; }
    public string Body { getset; }
    public string Email { getset; }
    public string Password { getset; }
}
 
 

Namespaces

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

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.
Note: For more details on how to use Model class object for capturing Form field values, please refer my article ASP.Net Core MVC: Form Submit (Post) example.
 
Inside this Action method, the posted values are captured through the EmailModel class object. All the fetched values are set into an object of the MailMessage class except the Body.
Setting Body of Email
For Body, an object of Builder class is created. The Body of the email is Text (Non HTML) hence it is set into the TextBody property of the Builder class object.
Setting Cc and Bcc Addresses
The Cc and Bcc addresses are fetched from the SMTP section of the AppSettings.jsonfile and are set into the object of the MimeMessage class.
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 AppSettings.json file and are passed as parameter to the Connect method.
Finally, the methods of Mail Server such as ConnectAuthenticateSend and Disconnect are executed and a success message is set into the ViewBag object.
public class HomeController : Controller
{
    public IConfiguration Configuration { get; set; }
 
    public HomeController(IConfiguration _configuration)
    {
        this.Configuration = _configuration;
    }
 
    public IActionResult Index()
    {
        return View();
    }
 
    [HttpPost]
    public IActionResult Index(EmailModel model)
    {
        //Read SMTP section from AppSettings.json.
        string host = this.Configuration.GetValue<string>("Smtp:Server");
        int port = this.Configuration.GetValue<int>("Smtp:Port");
        string ccAddress = this.Configuration.GetValue<string>("Smtp:CcAddress");
        string bccAddress = this.Configuration.GetValue<string>("Smtp:BccAddress");
 
        using (MimeMessage mm = new MimeMessage())
        {
            mm.From.Add(new MailboxAddress("Sender", model.Email));
            mm.To.Add(new MailboxAddress("Recipient", model.To));
            mm.Subject = model.Subject;
            mm.Cc.Add(new MailboxAddress("Cc", ccAddress));
            mm.Bcc.Add(new MailboxAddress("Bcc", bccAddress));
            BodyBuilder builder = new BodyBuilder();
            builder.TextBody = model.Body;
            mm.Body = builder.ToMessageBody();
            using (SmtpClient smtp = new SmtpClient())
            {
                smtp.Connect(host, port);
                smtp.Authenticate(model.Email, model.Password);
                smtp.Send(mm);
                smtp.Disconnect(true);
            }
        }
        ViewBag.Message = "Email Sent.";
        return View();
    }
}
 
 

View

Inside the View, the EmailModel class is declared as model for the View and ASP.Net TagHelpers in inherited.
The View consists of an HTML Form which has been created using the following TagHelpers attributes.
asp-action – Name of the Action. In this case the name is Index.
asp-controller – Name of the Controller. In this case the name is Home.
method – It specifies the Form Method i.e. GET or POST. In this case it will be set to POST.
The Form consists of HTML TextBox, TextArea element and a Submit Button.
When the Send Button is clicked, the Form gets submitted and the Model object is sent to the Controller.
Finally, the ViewBag object is checked for NULL and if it is not NULL then the value of the object is displayed using JavaScript Alert Message Box.
@addTagHelper*, Microsoft.AspNetCore.Mvc.TagHelpers
@model Send_Email_MailKit_Core_MVC.Models.EmailModel
@{
    Layout = null;
}
 
<!DOCTYPE html>
 
<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <title>Index</title>
</head>
<body>
    <form method="post" asp-controller="Home" asp-action="Index">
        <table>
            <tr>
                <td style="width: 80px">To:</td>
                <td><input type="text" asp-for="To" /></td>
            </tr>
            <tr><td>&nbsp;</td></tr>
            <tr>
                <td>Subject:</td>
                <td><input type="text" asp-for="Subject" /></td>
            </tr>
            <tr><td>&nbsp;</td></tr>
            <tr>
                <td valign="top">Body:</td>
                <td><textarea cols="20" rows="3" asp-for="Body"></textarea></td>
            </tr>
            <tr><td>&nbsp;</td></tr>
            <tr>
                <td>Gmail Email:</td>
                <td><input type="text" asp-for="Email" /></td>
            </tr>
            <tr><td>&nbsp;</td></tr>
            <tr>
                <td>Gmail Password:</td>
                <td><input type="password" asp-for="Password" /></td>
            </tr>
            <tr><td>&nbsp;</td></tr>
            <tr>
                <td></td>
                <td><input type="submit" value="Send" /></td>
            </tr>
        </table>
    </form>
    @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.
 
 

Screenshot

Email Form
Send Email with CC and BCC using MailKit in ASP.Net Core
 
Received Email
Send Email with CC and BCC using MailKit in ASP.Net Core
 
 

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