This is not a Postfix problem until you can demonstrate that Postfix fails to call postfwd.
smtpd_mumble_restrictions names and policy protocol activity are
logged with verbosity level=1. To turn this on selectively:
main.cf:
debug_peer_list = 10.1.2.0/24 10.3.4.0/24 (or whatever the Facebook outbound
hosts are)
debug_peer_level = 1
Wietse
