Pine

1. If the feature is enabled, you simply press "H" to toggle full headers.

If the feature is not enabled, you must enable it first

1. From the main menu, press (S)etup
   
2. (C)onfig.
   
3. Scroll down about 40 lines to the option labeled "enable-full-header-cmd."
   
4. Press [ENTER].
   
5. Press (E)xit,
   
6. (Y)es - to save.
   
7. Then you can return to the message window and use "H" to display the headers.