Email Delivery Service in Oracle Cloud Infrastructure for microservice components

We provide you with architecture where microservice component is implemented in the oracle cloud infrastructure, in the compute container instance

 In this architecture the OCI Email Service provides notification to the both users and customers and offline asynchronous synchronization between cloud component and customer on premise ERP application.

So there are many advantages to use OCI Email Delivery Service when deploying microservice to the OCI.

•  full control of features
• reliable and guaranteed
• scalable
• worlwide and distributable and deployabl ein the region where you using it

 3. Set up DKIM

DomainKeys Identified Mail (DKIM) lets the receiving email provider verify that an email was sent and authorized by the owner of the sender's domain. DKIM is set up within DNS records to facilitate digital signing of emails. You can configure up to two DKIMs for rotation purposes, and only one DKIM can be active for your domain at a time 

 More information here 

Click add DKIM. Provide the DKIM Selector and after click Generate DKIM Record and click Create DKIM. Now we need to configure our DNS domain.

 

Go to your domain admin page and create CNAME record with the value it gives you. It can take up to 1 day until the status changes to Active, for us it took 30 minutes. 

 

 4. Create the approved sender

 

 5. Configure TXT in domain for SPF

 The SPF allows you to state which email servers are permitted to send email on behalf of your domain. Email receivers use SPF to detect email spoofing.  Without SPF, a spam or phishing email can be spoofed to appear to be from a legitimate domain.

Navigate to your approved sender. Under the three-dot menu, select View SPF.

 

 

 

6. The last but not least  Configure SMTP connection

 

 7. Some quarkus java code for the microservice component

application.properties 

 # SMTP Server Configuration
quarkus.mailer.from=xxxxxxxxxccw.sk
quarkus.mailer.username=ocid1.user.oc1..xxxxxx.com
quarkus.mailer.password=xxxxxxxxx
quarkus.mailer.host=smtp.xxxxxoci.oraclecloud.com
quarkus.mailer.port=587
quarkus.mailer.ssl=false
quarkus.mailer.start-tls=REQUIRED
 
  Uni<Void> sendMailUni = mailer.send(Mail.withHtml(dto.getEmail(), "Rezervovaný termín", body)
                .addBcc("xxxxxx.com")
                .addHeader("Reply-To", emailConfig.getNotificationEmailAddress()) //
                .addHeader("Auto-Submitted", "auto-generated"))
                .onFailure()
                .retry()
                .withBackOff(Duration.ofSeconds(this.timeBetweenResents))
                .atMost(this.numOfAttempts);

        sendMailUni
                .subscribe()
                .with(success -> {
                    Log.info("> Email sent successfully ! id: " + appointmentId);
                },
                        failure -> {
                            Log.error("> Failed to send email to customer! id: "
                                    + appointmentId + " - "
                                    + failure.getMessage());
                        });

    }