A Dockerfile for sending gmail messages from the command line!

Dockerfile.ssmtp

FROM ubuntu:latest

# NOTE: Don't use your real password. Get an App Password from here:
# https://myaccount.google.com/apppasswords

# To Build:
# `docker build --build-arg email=<GMAIL_ADDRESS> --build-arg password=<GMAIL_PASSWORD> -t ssmtp .`

# To Run:
# `docker run -e MSG="Some Message" -e TO_EMAIL="recipient@example.com" ssmtp:latest`

ARG GMAIL_ADDRESS
ARG GMAIL_PASSWORD

RUN apt-get update
RUN apt-get install -y ssmtp
RUN touch /etc/ssmtp/ssmtp.conf
RUN echo "root=${GMAIL_ADDRESS}" >> /etc/ssmtp/ssmtp.conf
RUN echo "mailhub=smtp.gmail.com:465" >> /etc/ssmtp/ssmtp.conf
RUN echo "FromLineOverride=YES" >> /etc/ssmtp/ssmtp.conf
RUN echo "AuthUser=${GMAIL_ADDRESS}" >> /etc/ssmtp/ssmtp.conf
RUN echo "AuthPass=${GMAIL_PASSWORD}" >> /etc/ssmtp/ssmtp.conf
RUN echo "UseTLS=YES" >> /etc/ssmtp/ssmtp.conf

RUN useradd -ms /bin/bash email_user
USER email_user

CMD echo ${MSG} | ssmtp ${TO_EMAIL}