wildwildangel/postfix-relay repository overview

⁠docker-alpine-postfix-relay

wildwildangel/postfix-relay is a simple Postfix SMTP relay Docker image based on Alpine Linux. It has no local authentication configured and is supposed to run in a trusted environment.

⁠Environment Variables

The entry point requires the following environment variables:

• SERVER_HOSTNAME: the hostname for this container;
• SMTP_SERVER: the address of the SMTP server to use.

The following environment variables are optional:

• SMTP_PORT (defaults to 587): the port of the target SMTP server (used together with SERVER_HOSTNAME);
• SMTP_USERNAME: the username to authenticate with. If it is not empty, then it is mandatory to pass one of SMTP_PASSWORD or SMTP_PASSWORD_FILE;
• SMTP_PASSWORD_FILE: the file containing the password of the authenticating user. The entry point script will read this file and assign its contents to the SMTP_PASSWORD variable;
• SMTP_PASSWORD: the password of the authenticating user;
• SMTP_NETWORKS (defaults to 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16): the list of networks that are allowed to relay emails via this server;
• DEBUG: set to yes to enable debugging (effectively executes set -x).