Postalserver.io TLS and SMTP Tweaks

postal.yml

general:
  # This can be changed to allow messages to be sent from multiple IP addresses
  use_ip_pools: true

web:
  # The host that the management interface will be available on
  host: fqdn.domain.tld
  # The protocol that requests to the management interface should happen on
  protocol: https

web_server:
  # Specify configuration for the Postal web server
  bind_address: 127.0.0.1
  port: 5000

smtp_server:
  # Specify configuration to the Postal SMTP server
  port: 25
  # Enable TLS
  tls_enabled: true
  # Certificate Path
  tls_certificate_path: /config/fqdn.domain.tld.crt
  tls_private_key_path: /config/fqdn.domain.tld.key
  # Enable Modern Ciphers
  tls_ciphers: 'HIGH:!MEDIUM:!LOW:!aNULL:!eNULL:!EXPORT:!DES:!MD5:!PSK:!RC4'
  # Removes orgin headers from messages to hide mail server details
  strip_received_headers: true
  # Sets the maximum size of email messages in megabytes
  max_message_size: 25

logging:
  # Specify options for the logging
  stdout: true

main_db:
  # Specify the connection details for your MySQL database
  host: 127.0.0.1
  username: root
  password: postal
  database: postal

message_db:
  # Specify the connection details for your MySQL server that will be house the
  # message databases for mail servers.
  host: 127.0.0.1
  username: root
  password: postal
  prefix: postal

rabbitmq:
  # Specify connection details for your RabbitMQ server
  host: 127.0.0.1
  username: postal
  password: postal
  vhost: postal

dns:
  # Specify the DNS records that you have configured. Refer to the documentation at
  # https://github.com/atech/postal/wiki/Domains-&-DNS-Configuration for further
  # information about these.
  mx_records:
    - fqdn.domain.tld
  smtp_server_hostname: fqdn.domain.tld
  spf_include: _spf.domain.tld
  return_path: rp.domain.tld
  route_domain: routes.domain.tld
  track_domain: track.domain.tld
  dkim_identifier: mcow
  domain_verify_prefix: postal-verification
  custom_return_path_prefix: psrp

smtp:
  # Specify an SMTP server that can be used to send messages from the Postal management
  # system to users. You can configure this to use a Postal mail server once the
  # your installation has been set up.
  host: 127.0.0.1
  port: 2525
  username: # Complete when Postal is running and you can
  password: # generate the credentials within the interface.
  from_name: Postal
  from_address: fqdn.domain.tld

rails:
  # This is generated automatically by the config initialization. It should be a random
  # string unique to your installation.
  secret_key: 841e2c9d8c0f98dfcaac56dcdf7b7f365ea3a9c93ceaa17099d37e53536dd0c2614c0829cf36af3ed5ae692b6479f9850e24c3ca26879d0d5485d8141ace01fd73ab43a6e77321da5aa954f8f35ec3d3f017978c666d535738238e7965edbdba8fabd9c860028bc56cdbbc7daf30cc84642fb4d4bda83f182ddcb815684fe65c