Since I can't find a solution that works with my config, I lean on you guys to help me out with this. I've installed postfix and dovecot on a CentOS server. Everything's running well. But when I try to send an e-mail from Outlook to tld that is not .com, server returns : Relay access denied. Here's the result from the postconf -n command alias_database = hash:/etc/aliases alias_maps = hash:/etc/aliases command_directory = /usr/sbin config_directory = /etc/postfix daemon_directory = /usr/libexec/postfix data_directory = /var/lib/postfix debug_peer_level = 2 home_mailbox = Maildir/ html_directory = no inet_protocols = all mailbox_size_limit = 104857600 mailq_path = /usr/bin/mailq.postfix manpage_directory = /usr/share/man message_size_limit = 20971520 mydestination = $myhostname, $mydomain, localhost, localhost.$mydomain newaliases_path = /usr/bin/newaliases.postfix readme_directory = /usr/share/doc/postfix-2.6.6/README_FILES sample_directory = /usr/share/doc/postfix-2.6.6/samples sendmail_path = /usr/sbin/sendmail.postfix setgid_group = postdrop smtp_tls_loglevel = 3 smtpd_tls_auth_only = yes smtpd_tls_cert_file = /etc/postfix/mailserver.pem smtpd_tls_key_file = /etc/postfix/mailserver.pem smtpd_tls_received_header = yes smtpd_tls_security_level = encrypt smtpd_tls_session_cache_timeout = 3600s tls_random_source = dev:/dev/urandom unknown_local_recipient_reject_code = 550 Here's the maillog error : Nov 23 13:26:24 website_name postfix/smtpd[16391]: extract_addr: input: <mrm@website_name.com> Nov 23 13:26:24 website_name postfix/smtpd[16391]: smtpd_check_addr: addr=mrm@website_name.com Nov 23 13:26:24 website_name postfix/smtpd[16391]: ctable_locate: move existing entry key mrm@website_name.com Nov 23 13:26:24 website_name postfix/smtpd[16391]: extract_addr: in: <mrm@website_name.com>, result: mrm@website_name.com Nov 23 13:26:24 website_name postfix/smtpd[16391]: fsspace: .: block size 4096, blocks free 23679665 Nov 23 13:26:24 website_name postfix/smtpd[16391]: smtpd_check_queue: blocks 4096 avail 23679665 min_free 0 msg_size_limit 20971520 Nov 23 13:26:24 website_name postfix/smtpd[16391]: > unknown[178.193.xxx.xxx]: 250 2.1.0 Ok Nov 23 13:26:24 website_name postfix/smtpd[16391]: < unknown[178.193.xxx.xxx]: RCPT TO:<[email protected]> Nov 23 13:26:24 website_name postfix/smtpd[16391]: extract_addr: input: <[email protected]> Nov 23 13:26:24 website_name postfix/smtpd[16391]: smtpd_check_addr: [email protected] Nov 23 13:26:24 website_name postfix/smtpd[16391]: ctable_locate: move existing entry key [email protected] Nov 23 13:26:24 website_name postfix/smtpd[16391]: extract_addr: in: <[email protected]>, result: [email protected] Nov 23 13:26:24 website_name postfix/smtpd[16391]: >>> START Recipient address RESTRICTIONS <<< Nov 23 13:26:24 website_name postfix/smtpd[16391]: generic_checks: name=permit_sasl_authenticated Nov 23 13:26:24 website_name postfix/smtpd[16391]: generic_checks: name=permit_sasl_authenticated status=0 Nov 23 13:26:24 website_name postfix/smtpd[16391]: generic_checks: name=reject_unauth_destination Nov 23 13:26:24 website_name postfix/smtpd[16391]: reject_unauth_destination: [email protected] Nov 23 13:26:24 website_name postfix/smtpd[16391]: permit_auth_destination: [email protected] Nov 23 13:26:24 website_name postfix/smtpd[16391]: ctable_locate: leave existing entry key [email protected] Nov 23 13:26:24 website_name postfix/smtpd[16391]: NOQUEUE: reject: RCPT from unknown[178.193.xxx.xxx]: 554 5.7.1 <[email protected]>: Relay access denied; from=<mrm@website_name.com> to=<[email protected]> proto=ESMTP helo=<[192.168.1.38]> Nov 23 13:26:24 website_name postfix/smtpd[16391]: generic_checks: name=reject_unauth_destination status=2 Nov 23 13:26:24 website_name postfix/smtpd[16391]: > unknown[178.193.xxx.xxx]: 554 5.7.1 <[email protected]>: Relay access denied Nov 23 13:26:24 website_name postfix/smtpd[16391]: smtp_get: EOF What's wrong with this? UPDATE : added to main.cf broken_sasl_auth_clients = yes smtpd_recipient_restrictions = permit_mynetworks permit_sasl_authenticated smtpd_sasl_auth_enable = yes smtpd_sasl_path = private/auth smtpd_sasl_security_options = noanonymous noplaintext smtpd_sasl_tls_security_options = $smtpd_sasl_security_options smtpd_sasl_type = dovecot UPDATE : EHLO EHLO mail.perflux.com 250-perflux.com 250-PIPELINING 250-SIZE 20971520 250-VRFY 250-ETRN 250-STARTTLS 250-ENHANCEDSTATUSCODES 250-8BITMIME 250 DSN