FROM debian:jessie 
RUN echo "deb http://debian.mirrors.ovh.net/debian/ jessie-backports main" >> /etc/apt/sources.list \
    && apt-get update && apt-get install -y \
        opensmtpd/jessie-backports \
    && apt-get clean \
    && rm -rf /var/lib/apt/lists/*

ENTRYPOINT ["/usr/sbin/smtpd", "-d"]