Thanks for trying out CloudMailin. We've done our best to create documentation that's helpful and contains the information you need. If you do need any help though feel free to contact us.
Remember, all the documentation is also open source, so if you think there's something you could improve feel free to also send us a pull request to the github account.
The Getting Started Guides cover getting CloudMailin setup and receiving your first emails.
The Receiving Email section covers a number of features and things that you need to know when working with CloudMailin such as the HTTP Status Codes and Using Your Own Domain.
If you're ready to start coding take a look at our Post Formats to see the format of the HTTP POST that CloudMailin will send to your web application.
Alternatively check out the Examples Section.
CloudMailin also allows you to send transactional emails. Take a look at our information here:
Sending Email with CloudMailin Outbound