postfix fatal: parameter "smtpd_recipient_restrictions"

[sjobeck]

• running 6.0.5_GA_2213.RHEL5-20100202220948
• every 1-3 days or so mail stops flowing altogether
• checking the "/var/log/maillog" shows the following:
• Jul 6 08:50:47 mail postfix/smtpd[10073]: fatal: parameter "smtpd_recipient_restrictions": specify at least one working instance of: check_relay_domains, reject_unauth_destination, reject, defer or defer_if_permit
• stopping & starting Zimbra makes it work again fine for another few days
• the error seems to be a red herring, since if this error were actually true, simply restart Zimbra would not resolve it, since it is suggesting something fatally misconfigured with postfix
• we will try to upgrade to latest stable release as soon as we can, but .... wondering if any one else is seeing this or knows how to resolve
• thanks everyone for your advice!