(,(message-font-lock-make-header-matcher
(concat "^\\([GBF]?[Cc][Cc]:\\|[Rr]eply-[Tt]o:\\|"
"[Mm]ail-[Cc]opies-[Tt]o:\\|"
"[Mm]ail-[Rr]eply-[Tt]o:\\|"
"[Mm]ail-[Ff]ollowup-[Tt]o:\\)" content))
(,(message-font-lock-make-header-matcher
(concat "^\\([GBF]?[Cc][Cc]:\\|[Rr]eply-[Tt]o:\\|"
"[Mm]ail-[Cc]opies-[Tt]o:\\|"
"[Mm]ail-[Rr]eply-[Tt]o:\\|"
"[Mm]ail-[Ff]ollowup-[Tt]o:\\)" content))