message-face-alist

message-face-alist is a variable defined in `message.el'.
Its value is

((bold . message-bold-region)
 (underline . underline-region)
 (default lambda
   (b e)
   (message-unbold-region b e)
   (ununderline-region b e)))

Documentation:
Alist of mail and news faces for facemenu.
The cdr of each entry is a function for applying the face to a region.