[Exim] Reverse DNS -- grounds for rejection?

Is a test like this grounds for rejecting mail?
I note that quite a few messagelabs servers don't reverse properly.

Thanks
Rory

acl:
# Warn if the sender host does not have valid reverse DNS.
warn message = X-Broken-Reverse-DNS: no host name found for IP address $sender_host_address
      !verify = reverse_host_lookup
      log_message   = "REVERSE: $sender_fullhost"

log:
2004-01-15 10:58:22 1Ah5Cg-0007IQ-FF H=(lon-msg-101.internethub.cliffordchance.net) [193.111.25.186]
                    Warning: "REVERSE: (lon-msg-101.internethub.cliffordchance.net) [193.111.25.186]"

--
Rory Campbell-Lange
<rory@???>
<www.campbell-lange.net>