When I send mail using ssmtp server and postfix in docker as a mailhub then I got an error like relay access denied. My /etc/postfix/main.cf file is as follows:-

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.

smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination myhostname = mail.monstorm.com mydomain = monstorm.com alias_maps = hash:/etc/aliases alias_database = hash:/etc/aliases mydestination = $myhostname, localhost.$mydomain, localhost relayhost = mynetworks = 127.0.0.0/8 10.13.15.0/24 10.13.10.0/24 [::]/128 [::ffff:127.0.0.0]/104 [::1]/128 mynetworks_style = subnet mailbox_size_limit = 0 recipient_delimiter = + inet_interfaces = all smtpd_sasl_auth_enable = yes broken_sasl_auth_clients = yes smtpd_recipient_restrictions = permit_sasl_authenticated,reject_unauth_destination

catatnight / docker-postfix

Relay access denied... #5