sender_net_accept_relay

To workaround the lack of DNS lookup in the relay code, I tried to use
sender_net_accept_relay.

Here's my config:

sender_net_accept_relay = 134.133.0.0/255.255.0.0
sender_host_reject_relay = *

So why did this happen?

1996-07-26 16:16:43 refused relay to sjoshi@??? from farhadspc [134.133.40.57]