Resurrecting config_docker.json. Moving docker related files to docker directory. Added copyright info.

docker/main.cf

@@ -0,0 +1,28 @@
+myorigin = mattermost.com
+myhostname = mattermost.com
+
+smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
+biff = no
+
+append_dot_mydomain = no
+
+readme_directory = no
+
+# TLS parameters
+smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
+smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
+smtpd_use_tls=no
+smtp_use_tls=no
+smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
+smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
+
+smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
+alias_maps = hash:/etc/aliases
+alias_database = hash:/etc/aliases
+mydestination = localhost, localhost.localdomain, localhost
+relayhost = 
+mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
+mailbox_size_limit = 0
+recipient_delimiter = +
+inet_interfaces = all
+inet_protocols = all