Just like that, once again, our application is finished. We've covered quite a bit in this chapter. We started by learning a little bit about the history and technical details of several email protocols (SMTP, POP3, and IMAP4), then learned how to interact with services based on those using the JavaMail API. In the process of doing so, we discovered the Jackson JSON Parser and used it to marshal and unmarshal POJOs to and from the disk. We used the ControlsFX class, BeanPathAdapter, to bind non-JavaFX-aware POJOs to JavaFX controls, and the Quartz Job Scheduling Library to execute code on a schedule. Finally, we wrapped up our application using the Java Service Wrapper to create installation artifacts.
We're left with what I hope is an application that is both interesting and helpful. There are several ways to improve on it, of course, if you feel so motivated. The account/rule data structure could be extended to allow defining global rules that are shared across accounts. The GUI...