README.md in simple_postmark-0.5.0 vs README.md in simple_postmark-0.5.1

@@ -76,9 +76,20 @@
   # => "b7bc2f4a-e38e-4336-af7d-e6c392c2f817"
 response['ErrorCode']
   # => 0
 ```
 
+## Testing
+
+Testing simple_postmark is, well, simple. ;)
+
+```ruby
+# config/environments/test.rb
+config.action_mailer.simple_postmark_settings = { api_key: 'POSTMARK_API_TEST', return_response: true }
+```
+
+With this setup, it will actually trigger a connection to the Postmark API, but Postmark will never send any emails and nothing will be delivered to your recipients.
+
 ## Contributing
 
 1. Fork it
 2. Create your feature branch (`git checkout -b my-new-feature`)
 3. Commit your changes (`git commit -am 'Added some feature'`)