The most valuable feature of the Amazon WorkMail for me is the SMC server. It makes my work much easier, especially since I often work with Spring Boot. There are many built-in APIs in Spring Boot that help with messaging. What I appreciate about it is that it simplifies the process. I don't need to write much code; I define the credentials in my properties or environment variables. The Java Message API, an internal API from Spring Boot, does most of the work. I set up the properties and connected them to the SMC server, and I can send emails.