>unverified_recipient_reject_code = 450 <<< 550
>unverified_sender_reject_code = 450 <<< 554
Weird, I'm getting the same results..
postconf | grep code
access_map_reject_code = 554
default_rbl_reply = $rbl_code Service unavailable; $rbl_class [$rbl_what]
blocked using $rbl_domain${rbl_reason?; $rbl_reason}
defer_code = 450
fault_injection_code = 0
invalid_hostname_reject_code = 501
maps_rbl_reject_code = 554
multi_recipient_bounce_reject_code = 550
non_fqdn_reject_code = 504
reject_code = 554
relay_domains_reject_code = 554
unknown_address_reject_code = 554
unknown_client_reject_code = 554
unknown_hostname_reject_code = 554
unknown_local_recipient_reject_code = 500
unknown_relay_recipient_reject_code = 550
unknown_virtual_alias_reject_code = 550
unknown_virtual_mailbox_reject_code = 550
unverified_recipient_reject_code = 550
unverified_sender_reject_code = 554
