Hey Brian, if you are on your Bluemix trial still you shouldn't have to worry about limits. That email is working for us, give it another try and if it's still not working for you we can figure something else out.
The API descriptions for "Retrieve and Rank" and "Natural Language Classifier" both list the free number of API calls at 1000 per month. This seems a bit low to fully implement and test a working application without incurring costs for the developer. Or are these limits not enforced during the first month of using Bluemix?