At the top of a message when you reply. For instance, an email from Bob Jones on December 5th at 9am to Millie Anderson with Subject “Test” would begin
There’s an application enumeration called “Header Detail” that offers as constants: all, custom, default, no headers. I’ve never used it (I don’t use Mail), but that’s where to go hunting. If it actually works, “custom” might be your answer.
I don’t think I’ve explained clearly. I would like the header information to be copied within the body of an email when I reply to someone so that it is easy to keep track of an email conversation, just as occurs easily in Entourage or Outlook.
I do not know of a way to do it entirely in Mail, but I use FastScripts Lite along with a modified version of John Gruber’s Non-Top-Posting Reply Script to modify the default reply format in Mail. You might be able to start with that and work up to the Outlook/Entourage-style format you want. The non-top-posting script only has to do a little bit of deletion and cursor positioning. What you want is a bit more complicated since you need to extract info from the “current message” and then insert it into the new reply message, but it is probably doable.