Postfix

Use this role to setup a Postfix mail server. It comes with the following additions:

• Mail-TLS-Helper
• Fail2ban
• optional: MTA-STS-Resolver
• optional: OnionMX
• optional: Unbound

General type of mail server configuration

You can select via the variable postfix_type a pre-defined set of configuraion options that best meets your needs.

• internet: Mail is send received directly using SMTP. TLS is enabled.
• internal: Mail is sent to another machine on the same network for delivery. TLS is disabled. Only listens on port 25.

Dual use of RSA and ECDSA certificates

Newer versions of Let's Encrypt clients (as of Certbot 2.0.0 or Dehydrated ) defaults to ECDSA certificates. This could be a problem with older mail servers which only support RSA ciphers. Postfix can use both RSA and ECDSA certificates at the same time.

If you use Dehydrated follow these steps:

• Add your domain to /etc/dehydrated/domains.txt:

  mx.example.org
  

• Add another entry to /etc/dehydrated/domains.txt for the RSA certificate and use the alias to force a different directory name:

  mx.example.org
  mx.example.org > mx.example.org_rsa
  

• Create the certificate's directory:

  mkdir /var/lib/dehydrated/certs/mx.example.org_rsa
  chmod 0700 /var/lib/dehydrated/certs/mx.example.org_rsa
  

• Create a config /var/lib/dehydrated/certs/mx.example.org_rsa/config with the following setting:

  KEY_ALGO="rsa"
  

• Obtain the certificate:

  dehydrated --cron
  

• Add all certificates to Postfix' main.cf:

  smtpd_tls_cert_file = /var/lib/dehydrated/certs/mx.example.org_rsa/fullchain.pem
  smtpd_tls_key_file = /var/lib/dehydrated/certs/mx.example.org_rsa/privkey.pem
  smtpd_tls_eccert_file = /var/lib/dehydrated/certs/mx.example.org/fullchain.pem
  smtpd_tls_eckey_file = /var/lib/dehydrated/certs/mx.example.org/privkey.pem
  

Variables

Required

Variable	Value	Default	Note
postfix_type	str	internet	Determines how to setup Postfix. Choose internet or internal

Scope: misc

Variable	Value	Default	Note
unbound_install	bool		True if you whish to install unbound
postfix_onionmx	bool		True to setup OnionMX delivery
postfix_tls_herlp	bool	True to setup Mail-TLS-Helper
postfix_mydestination	List		List with hostnames
postfix_mynetworks	List		List with network addresses

Scope: submission

Variable	Value	Default	Note
postfix_submission	bool		Set True to configure submission port settings
postfix_submission_smtpd_tls_cert_file	string		Path to TLS cert file
postfix_submission_smtpd_tls_key_file	string		Path to TLS key file
postfix_submission_non_tls_port	int		Port number for an additional (internal) submission port without TLS

Scope: SASL Auth

Variable	Value	Default	Note
postfix_smtpd_sasl_type	string
postfix_smtpd_sasl_path	string
postfix_smtp_sasl_auth_enabled	bool	no
postfix_smtp_sasl_auth_relay	string		Relay server which provides SASL-Auth
postfix_smtp_sasl_auth_user	string		Username for SASL authentication
postfix_smtp_sasl_auth_password	string		Password for SASL authenticatio