Authentication Milter Docker

Docker container that uses fastmail / authentication_milter for SPF, SenderID, DKIM and DMARC authentication. It can save result data to an SQLite database and send daily RFC compliant aggregate reports using its own SMTP integration or through a smarthost.

Database

If a database cannot be found, it is automatically created (data/dmarc_reports.sqlite).

Installation

git clone https://github.com/freddieleeman/authmilter_docker.git
cd authmilter_docker
docker build -t freddieleeman/authmilter_docker .

Data/ folder

The data/ folder contains the configuration files for both Mail::DMARC and Mail::Milter::Authentication. This folder is attached as a shared volume to the docker container. This folder is also used for storing the SQLite database and log file. It can also be used to share a private key for DKIM signing the aggregate report emails (see mail-dmarc.ini).

Configuration

data/mail-dmarc.ini = Mail::DMARC configuration file

data/authentication_milter.json = Mail::Milter::Authentication configuration file

Logging

Set 'logtoerr' to 1 in the authentication_milter.json configuration file. The log file authentication_milter.err is saved to the shared volume (docker: /config, host: ./data)

Start container (in restart modus)

Replace /path/to/data in the command below with the location of the data folder containing the configuration files.

docker run -d \
  -v /path/to/data:/config:rw \
  -p 127.0.0.1:12345:12345 \
  --name authmilter_docker \
  --restart unless-stopped \
  freddieleeman/authmilter_docker

Add to Postfix configuration

add inet:localhost:12345 to smtpd_milters = in the Postfix main.cf configuration file

Example crontab

To enable daily (at 4am) sending of aggregate reports add a crontab to the host with the following command:

0 4 * * * docker exec authmilter_docker sh -c "dmarc_send_reports"

Use "dmarc_send_reports --verbose" for more verbose output.

View reports in database

docker exec authmilter_docker sh -c "dmarc_view_reports"