title: Add Attachment base64 image in MailMessage and read it in html body
body: <p>Currently I have to send emails with <code>MailMessage</code> and <code>SmtpClient</code> but I need to send a picture that is currently in <code>base64</code> <code>string</code> within the <code>MailAddress</code> body. </p>
  
  <p>I have understood that it is necessary to put it in the <code>Attachment</code>, but I don't know how to put <code>base64</code> in <code>MailMessage</code> class and then read it in order to visualize image in the body of the email. I don't have url image path. </p>