feedmail-fill-to-cc-function

feedmail-fill-to-cc-function is a compiled Lisp function in `feedmail.el'.

(feedmail-fill-to-cc-function HEADER-END)

Smart filling of address headers (don't be fooled by the name).
The filling tries to avoid splitting lines except at commas. This
avoids, in particular, splitting within parenthesized comments in
addresses. Headers filled include From:, Reply-To:, To:, Cc:, Bcc:,
Resent-To:, Resent-Cc:, and Resent-Bcc:.