walnut.js/dist/var/example.com/config.json

{ "mailgun.org": {
    "apiKey": "key-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
  , "apiPublicKey": "pubkey-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
  , "auth": {
      "user": "mailer@example.com"
    , "pass": "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
    , "api_key": "key-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
    , "domain": "example.com"
    }
  }
}