instantlinux/postfix repository overview

⁠postfix

The postfix daemon in a small Alpine Linux container, with client support for separate spamassassin container. This is a layer which supports related image postfix-python⁠.

⁠Usage

Configuration is defined as files in a volume mounted as /etc/postfix/postfix.d. Within that directory:

• Define your local settings as key = value pairs in postfix.cf; these will be added/updated into main.cf (via postconf).

• Define aliases in aliases.

• Name any map files you need such as virtusertable with a .map suffix (such as /etc/postfix/postfix.d/virtusertable.map).

• Define local users (if not using directory service) as users.sh.

See etc-example directory and kubernetes.yaml / docker-compose.yml.

⁠Variables

⁠Secrets

Look for sasl_passwd in SASL_README.html⁠ for the format of the postfix-sasl-passwd secret.

Also, if you're using TLS, create a secret containing the SSL private key and reference it in your smtpd_tls_key_file directive as shown in the example.

⁠Upgrade Notes

In versions 3.5.9 or later, there is a breaking change affecting the postalias command used to generate binary db files at startup. If you have an entry in any of your .cf files under /etc/postfix that look like:

alias_database = hash:/etc/postfix/aliases

change them to:

alias_database = lmdb:/etc/postfix/aliases

You will no longer see the error message:

postalias: fatal: unsupported dictionary type: hash. Is the postfix-hash package installed?

⁠Contributing

If you want to make improvements to this image, see CONTRIBUTING⁠.