This may be bad using Microsoft on this forum, but I have an issue with Postfix relay to MS Office 365. I can send to internal addresses, but not external. I receive the following error message: 550 5.7.1 Client does not have permissions to send as this sender (in reply to end of DATA command)) I have setup a Microsoft SMTP server and it works fine, both internal and external, but Postfix will not deliver to external addresses. I know it has to be a configuration issue. I just can't pinpoint what it is. I really would prefer to use Postfix. I've used it before and never had any issues, but if I don't figure this out, I will have to go with MS Here is my main.cf: # See /usr/share/postfix/main.cf.dist for a commented, more complete version # Debian specific: Specifying a file name will cause the first # line of that file to be used as the name. The Debian default # is /etc/mailname. myorigin = /etc/mailname smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu) biff = no # appending .domain is the MUA's job. append_dot_mydomain = no # Uncomment the next line to generate "delayed mail" warnings #delay_warning_time = 4h readme_directory = no # TLS parameters smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key smtpd_use_tls=yes smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache # See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for # information on enabling SSL in the smtp client. myhostname = mailrelay.mydomain.com mydomain=mydomain.com relay_domains=* alias_maps = hash:/etc/aliases alias_database = hash:/etc/aliases myorigin = /etc/mailname mydestination = mailrelay.mydomain.com, localhost.mydomain.com, , localhost relayhost = [pod51019.outlook.com]:587 mynetworks = 192.168.86.178, 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 mailbox_size_limit = 0 recipient_delimiter = + inet_interfaces = all smtp_sasl_auth_enable = yes smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd smtp_sasl_security_options = noanonymous smtp_tls_CAfile = /etc/postfix/cacert.pem smtp_generic_maps = hash:/etc/postfix/generic smtp_sasl_mechanism_filter = login smtp_tls_loglevel = 1 smtp_tls_security_level = may smtp_send_dummy_mail_auth = yes
