Simple double opt-in so that website visitors can subscribe to your Mailgun mailing lists.
docker run -d
-p 8080:8080 \
-e "API_KEY=..." \
-e "BASE_URL=..." \
-e "DOMAIN=..." \
-e "FROM=..." \
-e "MAILING_LIST_ADDRESS=..." \
-e "TOKEN_SECRET=..." \
choffmeister/newsletter-subscribe:latest