docs: about how to prevent sending certain notifications type through…

… email

README.md

@@ -203,6 +203,12 @@ sequenceDiagram
 > If the email sent in the `PUT /set-email` request is an empty string, the email will be removed from the subscription and email notifications will be 
 > deactivated for the user.
 
+### Prevent sending emails for certain type of notifications
+Currently, the service broadcasts notifications both via email and in-world inboxes. Whenever a new notification is added, the service attempts to deliver it through both channels. However, certain notifications should be broadcasted exclusively in-world to avoid cluttering users’ email inboxes.
+
+The service will attempt to send email notifications if a corresponding template is available in the `processor/src/adapters/email-templates/` directory. To prevent a notification from being sent via email and only broadcast it in-world, simply avoid adding or remove the email template for that notification from this directory.
+
+Additionally, the service tests must be adjusted since they automatically check for a matching template for every notification type. For notifications intended to be broadcasted only in-world, it is needed to exclude them from the test suite located at `/processor/test/unit/adapters/email-renderer.spec.ts`, as has already been done for the `BADGE_GRANTED` notification type.
 
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