Hi, I've posted this as a serverfault [1]question but had no bites so far.
I am receiving about 50 rejected emails per day because there is a typo in the sending email address and it's hitting reject_unknown_sender_domain: Jul 10 12:21:31 serverb3 postfix/smtpd[6647]: NOQUEUE: reject: RCPT from smtp.correctly-spelt-domain.co.uk[X.X.X.X]: 450 4.1.8 <em...@mis-spelt-domain.co.uk>: Sender address rejected: Domain not found; from=<em...@mis-spelt-domain.co.uk> to=<em...@mydomain.co.uk> proto=ESMTP helo=<smtp.correctly-spelt-domain.co.uk> I've added em...@mispelt-domain.co.uk OK to /etc/postfix/sender_access, ran postmap /etc/postfix/sender_access and restarted postfix. Despite check_sender_access hash:/etc/postfix/sender_access appearing in my smtpd_recipient_restrictions list before reject_unknown_sender_domain the emails are still being rejected for that reason. Why is this and how can I fix it? Postfix v2.11.3 Output of postconf -n: alias_database = hash:/etc/aliases alias_maps = hash:/etc/aliases biff = no command_directory = /usr/sbin config_directory = /etc/postfix daemon_directory = /usr/lib/postfix disable_vrfy_command = yes home_mailbox = Mail/ mailbox_command = /usr/lib/dovecot/deliver mailbox_size_limit = 0 message_size_limit = 20480000 mydestination = b3.localdomain, localhost.localdomain, localhost, /etc/postfix/bubbadomains, $myhostname mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 recipient_delimiter = + relayhost = smtp.gmail.com sender_bcc_maps = hash:/etc/postfix/sender_bcc smtp_sasl_auth_enable = yes smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd smtp_sasl_security_options = noanonymous smtp_tls_session_cache_database = btree:${queue_directory}/smtp_scache smtp_use_tls = yes smtpd_banner = $myhostname ESMTP $mail_name (Debian/GNU) smtpd_helo_required = yes smtpd_recipient_restrictions = permit_mynetworks check_sender_access hash:/etc/postfix/sender_access reject_unauth_destination reject_unauth_pipelining reject_invalid_hostname reject_non_fqdn_sender reject_unknown_sender_domain reject_non_fqdn_recipient reject_unknown_recipient_domain reject_rbl_client bl.spamcop.net reject_rbl_client zen.spamhaus.org reject_rbl_client dul.dnsbl.sorbs.net permit smtpd_reject_unlisted_sender = yes smtpd_relay_restrictions = permit_mynetworks reject_unauth_destination reject_unauth_pipelining reject_invalid_hostname reject_non_fqdn_sender reject_unknown_sender_domain reject_non_fqdn_recipient reject_unknown_recipient_domain check_sender_access hash:/etc/postfix/sender_access reject_rbl_client bl.spamcop.net reject_rbl_client zen.spamhaus.org reject_rbl_client dul.dnsbl.sorbs.net permit smtpd_tls_cert_file = /etc/letsencrypt/live/mydomain.co.uk/fullchain.pem smtpd_tls_key_file = /etc/letsencrypt/live/mydomain.co.uk/privkey.pem smtpd_tls_session_cache_database = btree:${queue_directory}/smtpd_scache smtpd_use_tls = yes unknown_local_recipient_reject_code = 550 PS. I have also tried to address the root cause by contacting the owners of the domain in question and informing them. I am not holding my breath they will fix it. Thanks. Darren. Links: ------ [1] https://serverfault.com/questions/861268/postfix-ignoring-order-of-smtpd-recipient-restrictions