hi all the following is the log from my relay for example.com; this is read receipt which failed; this is happening only with this client domain;
Nov 18 20:13:59 relay2 postfix/smtpd[4225]: NOQUEUE: reject: RCPT from ex.2n.cz[90.182.112.11]: 451 4.3.5 Server configuration error; from=<> to=< a...@example.com> proto=ESMTP helo=<ex.2n.cz> Nov 18 20:13:59 relay2 postfix/smtpd[4225]: disconnect from ex.2n.cz [90.182.112.11] the below is my restrictions: smtpd_helo_required = yes smtpd_helo_restrictions = smtpd_recipient_restrictions = reject_non_fqdn_recipient reject_non_fqdn_sender reject_unknown_sender_domain reject_unknown_recipient_domain permit_mynetworks reject_unauth_destination check_recipient_access hash:/etc/postfix/roleaccount_exceptions check_client_access hash:/etc/postfix/backscatterer_whitelist check_sender_access hash:/etc/postfix/check_backscatterer reject_non_fqdn_hostname reject_invalid_hostname check_client_access cidr:/etc/postfix/spam_cidr check_helo_access pcre:/etc/postfix/helo_checks check_recipient_access hash:/etc/postfix/whitelist_recipients reject_rbl_client zen.spamhaus.org reject_rhsbl_sender dsn.rfc-ignorant.org permit smtpd_data_restrictions = reject_multi_recipient_bounce reject_unauth_pipelining permit smtpd_sender_restrictions = hash:/etc/postfix/access check_sender_access hash:/etc/postfix/strict_sender_map smtpd_restriction_classes = strict_client_domain strict_client_domain = reject_unknown_client check_client_access hash:/etc/postfix/strict_client_map reject smtpd_use_tls = no strict_8bitmime = no strict_rfc821_envelopes = no transport_maps = hash:/etc/postfix/transport unknown_client_reject_code = 554 unknown_local_recipient_reject_code = 550 virtual_alias_domains = hash:/etc/postfix/virtual virtual_alias_maps = hash:/etc/postfix/virtual pcre:/etc/postfix/virtual_pcre -is anything wrong with my settings?! help appreciated