Docker image to run HAProxy for proxying SMTP.
Proxy SMTP from localhost:25000 to example.com:25:
docker run -p 25000:25000 -e SMTP_DESTINATION='example.com:25' cargomedia/smtp-proxy
The server exposes a health check at /healthz on port 8888.
Build the image:
docker build -t cargomedia/smtp-proxy .
The image will be pushed to Docker Hub by the travis build.