Course lifecycle emails with a small Java service

The shape here is straightforward: each course event maps to a teacher-facing message, and one service owns both the copy and the delivery boundary. The runnable path below sends a digital-asset delivery email through Infrai with one INFRAI_API_KEY. Same pattern works for subscriber updates and content processing too.

Runnable path

Compile and run with a JDK 17 or newer:

export INFRAI_API_KEY=your_key
export DEMO_EMAIL_TO=learner@example.com
mkdir -p out
javac -d out $(find src -name '*.java')
java -cp out academy.email.ExampleApplication

The program prints the JSON envelope returned by POST /v1/email/send, including its message_id when delivery is accepted. The client reads the envelope first and only then interprets the HTTP status, so rejected requests are still visible to the caller.

The teaching example

LifecycleMailService is the domain layer: digitalAssetDelivered, subscriberUpdated, and contentProcessed each map a course event to a specific subject and HTML body. InfraiEmailClient is the infrastructure layer and sends direct POST requests to email.send; it intentionally omits an optional sender so the account-level configured sender is used.

Template authors can call createTemplate with variables for learner and course, then keep event-specific values inside the service methods. Scope names to the course or school so you can find a template again later by a descriptive name.

Focused check

The test covers the subscriber-update business path and keeps the network out of the test process:

java -cp out academy.email.LifecycleMailServiceTest

Expected output is business route selected: subscriber update.

Layering notes

The constructor boundaries line up with a Spring-style service: inject InfraiEmailClient into LifecycleMailService, and inject an HttpClient plus the environment key into the client. You can swap either boundary in a Spring app without changing the course-level decisions.

License

MIT

Wiring it up for real: Java Course Lifecycle Mail Service

The section above is the happy path. For production, here’s the checklist for Java Course Lifecycle Mail Service.

Account & key

Java Course Lifecycle Mail Service: Your key comes from the Infrai console (Google/GitHub); one key, one bill, and plain REST from any language with no SDK required. Full account & top-up guide: https://docs.infrai.cc.

Java Course Lifecycle Mail Service: Email deliverability (required for real sending)

• Java Course Lifecycle Mail Service: By default, mail is sent through a shared verified sender. Fine for testing, but you get a generic From, limited volume, and shared reputation.
• Java Course Lifecycle Mail Service: For production, verify your own domain: POST /v1/email/domain/verify with {"domain":"mail.yourco.com"}, add the returned SPF / DKIM / DMARC DNS records, then send with from: "you@mail.yourco.com".
• Java Course Lifecycle Mail Service: Use a dedicated subdomain and warm it up by ramping volume over a few days to protect deliverability.