title: Maximum size of email X-Headers
body: <p>We are looking at sticking some metadata into the X-Headers of email messages. These emails are for consumption by internal systems, and will be hosted on an Exchange server.</p>
  
  <p>Is there a maximum size for the ammount of data that we can store in an X-Header? </p>
  
  <p>Are there any limitations, such as special characters, that I should know about?</p>