ansible_role_mailserver/defaults/main.yml

#
# Default variables for the role. These can be overridden in your inventory
# or playbook to customize the deployment.
#

# The Internet protocols Postfix will attempt to use when making or accepting connections. Specify one or more of "ipv4" or "ipv6", separated by whitespace or commas.
# The form "all" is equivalent to "ipv4, ipv6" or "ipv4", depending on whether the operating system implements IPv6.
postfix_inet_protocols: "all"

# The local network interface addresses that this mail system receives mail on. Specify "all" to receive mail on all network interfaces (default),
# "loopback-only" to receive mail on loopback network interfaces only (Postfix version 2.2 and later), or zero or more IPv4 or IPv6 addresses 
# (IPv6 is supported in Postfix version 2.2 and later)
postfix_inet_interfaces: "all"

# The primary mail domain for this server.
postfix_mail_domain: "{{ ansible_domain | default('internal.local') }}"

# The Fully Qualified Domain Name of the mail server.
postfix_myhostname: "mail.{{ postfix_mail_domain }}"

# Comma-separated list of domains this server accepts mail for.
# It's critical that this includes the server's own hostname and mail domain.
postfix_mydestination: "$myhostname, localhost.{{ postfix_mail_domain }}, localhost, {{ postfix_mail_domain }}"

# The list of "trusted" remote SMTP clients that have more privileges than "strangers".
postfix_mynetworks: "127.0.0.0/8 [::1]/128"

# The relayhost (smarthost) for all outgoing mail.
# This variable MUST be set for the role to work as intended.
# Example: "[smtp.sendgrid.net]:587"
# Note: The square brackets [] are important to prevent MX record lookups.
postfix_relayhost: ""

# Optional credentials for the relayhost. If these are defined,
# SASL authentication will be automatically configured.
# postfix_relayhost_user: "apikey"
# postfix_relayhost_password: "YourVeryLongAndComplexApiKey"