You are working in a new Node.js repository. Integrate the {{PROVIDER}} email API and complete this task:

1. Install the provider's official server-side SDK when one exists; otherwise use its documented REST API.
2. Read credentials only from {{CREDENTIAL_ENV}}. Never print, copy, or commit the credential.
3. Implement a script that sends one transactional verification email to {{TEST_RECIPIENT}} with the subject "All Them APIs verification" and a unique run ID in the body.
4. Use the provider's documented sandbox, test mode, or non-delivery recipient when available. Do not silently replace the requested recipient or return demo data.
5. Add an automated test for request construction and a README containing install, run, and cleanup commands.
6. Run the test and the script. Record the provider message ID or the exact blocking error.

Success requires a provider-confirmed message ID or a documented non-delivery test response, passing local tests, no secret in the repository, and no change to the requested behavior. If authorization or account state blocks the task, stop and report the exact step.