Build ASP.NET Core Website

Last Updated: 7/1/2025

Send Email

In this article, you will see how to send email from ASP.NET Core Website using MailKit.

Install the Required Packages

Install-Package MailKit
Install-Package MimeKit

Send Email using MailKit

Basic code for sending email.

var email = new MimeMessage();
email.From.Add(MailboxAddress.Parse("[from-email]"));
email.To.Add(MailboxAddress.Parse("[to-email]"));
email.Subject = "[subject]";

var builder = new BodyBuilder();
builder.HtmlBody = "[body]";
email.Body = builder.ToMessageBody();

using var smtp = new SmtpClient(new ProtocolLogger("smtp.log"));
smtp.ServerCertificateValidationCallback = (s, c, h, e) => true;
smtp.Connect("[host]", "[port]", SecureSocketOptions.Auto);
smtp.Authenticate("[username]", "[password]");
await smtp.SendAsync(email);
smtp.Disconnect(true);

Replace the content in the square brackets with actual value.

Attachments

attachments is of type List<IFormFile>

byte[] fileBytes;
foreach (var file in attachments)
{
    if (file.Length > 0)
    {
        using (var ms = new MemoryStream())
        {
            file.CopyTo(ms);
            fileBytes = ms.ToArray();
        }
        builder.Attachments.Add(file.FileName, fileBytes, ContentType.Parse(file.ContentType));
    }
}

Fake Email Provider

Ethereal - a fake SMTP service.

https://ethereal.email/

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