postfix - configure trusted hosts

Hi,

Can anyone tell me what's the reason it's not possible to set up an kind of
whitelist so some trusted hosts can bypass all checks.

In my main.cf i have added an remote sales office mail server (61.177..),
unfortunately this hosts is still beeing blocked when i re-activate the
check "reject_unknown_helo_hostname"
My idea was that the first rule it hit was permit_mynetworks and then the
mail would be accepted.....

mynetworks = 192.168.100.7, 61.177.163.164

smtpd_client_restrictions = check_client_access
hash:/usr/local/etc/postfix/incoming-ip-blocked,
reject_rbl_client zen.spamhaus.org,

smtpd_helo_restrictions = permit_mynetworks,
check_helo_access
hash:/usr/local/etc/postfix/incoming-ip-blocked,
reject_invalid_helo_hostname,
reject_non_fqdn_helo_hostname,
#reject_unknown_helo_hostname,
permit