message-bogus-recipient-p
message-bogus-recipient-p is a compiled Lisp function in `message.el
'.
(message-bogus-recipient-p RECIPIENTS)
Check if a mail address in RECIPIENTS looks bogus.
RECIPIENTS is a mail header. Return a list of potentially bogus
addresses. If none is found, return nil.
An address might be bogus if the domain part is not fully
qualified, see `message-valid-fqdn-regexp', or if there's a
matching entry in `message-bogus-addresses'.