Update Let's Encrypt account email using Certbot Docker image

I changed my email provider and realised my Let's Encrypt certificate expiry warnings were still going to the old address. Since I run Certbot as a Docker container, updating the account email is a single docker run away.

Replace /path/to/conf with your Certbot configuration directory and john@example.org with the new address:

docker run --rm \
  --volume /path/to/conf:/etc/letsencrypt \
  certbot/certbot --verbose update_account --email john@example.org

The volume mount is the important part: update_account writes to /etc/letsencrypt/accounts/, so that directory must be the same one your renewal cron job uses. No webroot volume needed, no interactive session, just the config directory.