FROM debian:stretch-slim # Install exim4 ENV DEBIAN_FRONTEND noninteractive RUN set -ex; \ apt-get update; \ apt-get install -y exim4-daemon-light; \ apt-get clean COPY docker-entrypoint.sh /usr/local/bin/docker-entrypoint.sh EXPOSE 25/tcp ENTRYPOINT [ "docker-entrypoint.sh" ] CMD [ "exim", "-bdf", "-v", "-q30m" ]