In Mac OS X Mail, how do I display and send the full headers of an email message?

In Mac OS X Mail, to send the full headers of an email message you have received, you must first display the headers:

• In Mail 1.3 for OS X 10.3.x (or later), select the message and then, from the View menu, select Message and then Long Headers.
  
  
• In Mail 1.2.5 for OS X 10.2.x (and earlier), select the message and then, from the View menu, select Show All Headers.

To send the full headers in an email message, with the headers displayed, from the Message menu, select Forward, Forward Message, Reply, or Reply to Sender, as appropriate. Mail will include the headers along with the message in the quoted text in your message.

Also see:

• In Mac OS X Mail, how do I set up incoming mail filters?
• In email, what are full headers, and how do I display and send them?
• In Mac OS X Mail, how do I remove SMTP servers?
• Working with attachments in Mac OS X Mail
• In Mac OS X Mail, how can I turn spell checking off or on?
• In Mac OS X Mail, how do I append other messages to the message I am currently composing?