Add SMTP_HEADER_CHECKS and ALLOW_EMPTY_SENDER_DOMAINS

Three new exiting features in this release:

• Allow setting empty sender domains from PR #17
• Add SMTP_HEADER_CHECKS from PR #15
• A script to build the image with custom alpine version from PR #20

One important feature: Multi-platform build (Yay!)

This release switches from Docker hub build to GitHub Actions. These allow us to use docker buildx. As a result, this image is available for more platforms than ever:

• linux/386
• linux/amd64
• linux/arm/v6
• linux/arm/v7
• linux/arm64
• linux/ppc64le

Just use the image as standard - boky/postfix:latest - docker will do the rest

More robust support for DKIM

DKIM support was a bit more optimized:

• OpenDKIM now listens on 0.0.0.0 (as it's in the container anyway), as listening to localhost had its issues
• DKIM will now sign more header tags

Fix for Alpine 3.9 cyrus-sasl split

This is a minor update that just installs additional packages to resolve https://bugs.alpinelinux.org/issues/9987.

Simplified DKIM support

This a minor upgrade to v1.1.0: DKIM was retooled to look for private keys in /etc/opendkim/keys/ and not in subfolders.

This should make it much easier to use the image with Kubernetes and such.

DKIM Support

This release features an initial support for DomainKeys Identified Mail (DKIM) inside the container image.

Just create the keys using:

opendkim-genkey -s mail -d example.org

and mount the keys into /etc/opendkim/keys.

More information is available in README.md.

Happy 2019

This is the first "official release" of the Docker postfix container.

See README.md for details on how to run it. Some samples are in the sample directory.

Major changes since the latest (unreleased) version:

• TZ environment variable to set the timezone of the container
• Better support for TLS connections to relay severs using the RELAYHOST_TLS_LEVEL variable and referencing the ca-certificates.crtfile
• Ability to setMESSAGE_SIZE_LIMIT for email messages
• The possibility to enable debugging with INBOUND_DEBUGGING parameter
• ALLOWED_SENDER_DOMAINS is now a required parameter as newer versions of postfix won't start without it

Minor changes:

• some nice colours of log files if running in terminal
• bash was removed from the container as the script is 100% sh-compatible