title: What is the difference between X-Priority vs Priority headers when working with SMTP?
body: <p>I am using MailKit as SMTP client to send emails.</p>
  <p>I see there are two properties <a href="https://github.com/jstedfast/MimeKit/blob/778ca3f1ac1d3edb16f9adb8894097218d37f742/MimeKit/XMessagePriority.cs" rel="nofollow noreferrer">XMessagePriority</a> and <a href="https://github.com/jstedfast/MimeKit/blob/778ca3f1ac1d3edb16f9adb8894097218d37f742/MimeKit/MessagePriority.cs" rel="nofollow noreferrer">MessagePriority</a></p>
  <p>what is the difference between these two and does one override the other?</p>