======== Required information ====
- iRedMail version (check /etc/iredmail-release): 0.9.0
- Linux/BSD distribution name and version: Centos 6
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): PGSQL
- Web server (Apache or Nginx): Apache
- Manage mail accounts with iRedAdmin-Pro? 1.5.2
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

hi zhang,

i'me see lots of below mentioned errors in my '/var/log/maillog', within the same domain for one user to another user as well as external domains.

postfix/smtpd[1526]: NOQUEUE: reject: RCPT from unknown[a.b.c.d]: 451 4.3.5 Server configuration problem; from=<abc@xxx.com> to=<def@xxx.com> proto=ESMTP helo=<xxx.com>

i've searched thru the topics and tried the methods, doesn't seems like working.

what could be the issue here.

my postconf smtpd_recipient_restrictions :

smtpd_recipient_restrictions = reject_unknown_sender_domain, reject_unknown_recipient_domain, reject_non_fqdn_sender, reject_non_fqdn_recipient, reject_unlisted_recipient, check_policy_service inet:127.0.0.1:7777, check_policy_service inet:127.0.0.1:10031, permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination