title: DKIM using MIMEKIT
body: <p>Im trying to DKIM sign all my emails using MIMEKIT and it works flawless for email body of smaller lenght but when content/size of email body increases., DKIM fails.
  Im generating the body using "BodyBuilder".</p>
  
  <p>The following are my doubts in MIMEKIT</p>
  
  <p>Is there any limitation in body/content length?.
  Is it Mandatory to give both text and html format of the content for DKIM sign?</p>
  
  <p>Below is my code for reference:</p>
  
  <pre><code>var message = new MimeMessage();
  message.From.Add(new MailboxAddress("Sender", "abc@xyz.com"));
  message.To.Add(new MailboxAddress("Mr K", ""k@abc.com"));
  message.Subject = "Hi";
  message.Sender = new MailboxAddress("realsender", "realsender@rtg.com");
  message.InReplyTo = "realsender@rtg.com";
  var builder = new BodyBuilder();
  builder.TextBody = strbodytxt;
  builder.HtmlBody = strbody;
  builder.Attachments.Add(strattachmentpath);
  message.Body = builder.ToMessageBody();
  </code></pre>