When I am trying to send a mail using MailKit that has a html body with embedded images, the images are showing in the email body but also as attachments.

I don’t want attachments, just as mail body like the following

The code for my mailbody composition is as follows:

 private async Task<MimeMessage> MailCompose(Command request)
 {
     var to = request.EmailAddresses.Select(x => MailboxAddress.Parse(x));
     var message = new MimeMessage();
     message.From.Add(MailboxAddress.Parse(request.MailSettingsRequest.SMTPEmailID));
     message.To.AddRange(to);
     message.Subject = request.EmailTemplateRequest.TemplateSubject;

     message.Body = UpdateImageTags(request.EmailTemplateRequest.MessageBody).ToMessageBody();
     return message;
 }
 static BodyBuilder UpdateImageTags(string input)
 {
     var bodyBuilder = new BodyBuilder();
     string pattern = @"<img[^>]*s+src=['""]([^'""]+)['""][^>]*>"; // Regex to match <img> tags and extract src
     MatchCollection matches = Regex.Matches(input, pattern);

     foreach (Match match in matches)
     {
         string imgTag = match.Value;
         string srcValue = match.Groups[1].Value;

         // Check if src is base64
         if (srcValue.StartsWith("data:image/"))
         {
             // Extract base64 string
             string base64Data = srcValue.Substring(srcValue.IndexOf(",") + 1);
             string imageFormat = srcValue.Substring(5, srcValue.IndexOf(";") - 5); // Get image format (e.g., png, jpeg)

             // Convert base64 to linked resource and add to BodyBuilder
             byte[] imageBytes = Convert.FromBase64String(base64Data);
             var stream = new MemoryStream(imageBytes);

             var id = MimeUtils.GenerateMessageId();
             var newpart = new MimePart()
             {
                 ContentId = id,
                 Content = new MimeContent(stream),
                 ContentDisposition = new ContentDisposition(ContentDisposition.Inline),
                 ContentTransferEncoding = ContentEncoding.Base64
             };
             
             bodyBuilder.LinkedResources.Add(newpart);
             
             string newImgTag = $"<img src='cid:{id}' />"; 
            
             input = input.Replace(imgTag, newImgTag);
         }
     }
     bodyBuilder.HtmlBody = input;
     return bodyBuilder;
 }

And sample MessageBody that I am getting from the editor is(the full image byte is omitted for brevity)-

"<p>this is a image email</p>n<p><img src="data:image/png;base64,iVBORw0KGgoA..."></p>