mail-header

mail-header is a compiled Lisp function in `mailheader.el'.

(mail-header HEADER &optional HEADER-ALIST)

Return the value associated with header HEADER in HEADER-ALIST.
If the value is a string, it is the original value of the header. If the
value is a list, its first element is the original value of the header,
with any subsequent elements being the result of parsing the value.
If HEADER-ALIST is nil, the dynamically bound variable `headers' is used.