Realtime Blacklist (RBL) Checker

This docker container regularly checks one or multiple email servers against a number of RBL blacklists in a customizable interval. If one of the specified server is listed on one or more blacklists, it sends a notification via Apprise.

Features

• Supports IPv4 and IPv6
• Notifications via Apprise whenever a new listing is found or an existing one is removed
• Runs inside a docker container, which is fully configurable by environment variables
• Optional integration of healthchecks.io

Usage

The container can be configured using environment variables. These are:

Variable	Mandatory/Optional	Usage
RBL_HOSTS	Mandatory	The hosts to monitor, given either as IP-Address or as FQDN. Multiple hosts have to be comma-separated. If a FQDN is provided, all available IPv4 and IPv6 addresses will be checked
RBL_APPRISE_URL	Mandatory	A string representing the notification endpoint. Format according to the Apprise Documentation
RBL_INTERVAL	Optional	The interval in which the blacklists should be checked, given in minutes. Default: 60
RBL_HEALTHCHECK_URL	Optional	This URL is fetched (GET-request) after each execution to indicate, that the service was executed. This may be used in conjunction with e.g. healthchecks.io. This is skipped, if the variable is not set
RBL_DQS	Optional	Spamhaus DQS key. It is recommended to supply this value, as otherwise false-positives may occur.

Run as a docker container

This container can be run with the following docker command:

docker run -d --name rbl-checker -e RBL_HOSTS=mail.example.com,mail.example.org -e RBL_APPRISE_URL=pover://abc@xyz sbonfert/rbl-checker

docker-compose example configuration

rbl-checker:
    image: sbonfert/rbl-checker:latest
    restart: always
    container_name: rbl-checker
    environment:
      - RBL_HOSTS=mail.example.com,mail.example.org
      - RBL_APPRISE_URL=pover://abc@xyz