feedmail-default-message-id-generator

feedmail-default-message-id-generator is a compiled Lisp function in `feedmail.el'.

(feedmail-default-message-id-generator MAYBE-FILE)

Default function for generating Message-Id: header contents.
Based on a date and a sort of random number for tie breaking. Unless
`feedmail-message-id-suffix' is defined, uses `user-mail-address', so be
sure it's set. If both are nil, creates a quasi-random suffix that is
probably not appropriate for you.