Mailgun Failed Webhook

This worker sends an email every time it receives a webhook from Mailgun indicating an email has failed. This lets you go in and see why, and fix any issues, without emails being dropped silently.

Set-up

1. Add the following environment variables to Cloudflare by using wrangler secret put:

       DOMAIN=domain.com
       [email protected]
       MAILGUN_API_KEY=
       MAILGUN_SIGNING_KEY=
   

   You can get your Mailgun API key from your domain property inside Mailgun, and your Mailgun Signing Key from the Webhook page of a domain in your Mailgun dashboard.

2. Change the account_id in wrangler.toml

3. (Optional) Create a Cloudflare API Key that lets you manage workers. Add this key to GitHub Secrets as CF_API_TOKEN

4. Caching is not supported on the workers.dev domain so this needs to be deployed to a custom domain to prevent replay attacks

Developing and Publishing with Wrangler

Install dependencies

    npm i

Start the development environment

    wrangler login
    wrangler dev

Publish

    wrangler publish