fix: send mail to opted in users for trial instance in MessageService

https://gravitee.atlassian.net/browse/APIM-4276

gravitee-apim-rest-api/gravitee-apim-rest-api-service/src/main/java/io/gravitee/rest/api/service/impl/MessageServiceImpl.java

@@ -27,6 +27,8 @@
 import io.gravitee.repository.management.model.Subscription;
 import io.gravitee.rest.api.model.*;
 import io.gravitee.rest.api.model.application.ApplicationListItem;
+import io.gravitee.rest.api.model.parameters.Key;
+import io.gravitee.rest.api.model.parameters.ParameterReferenceType;
 import io.gravitee.rest.api.model.permissions.RoleScope;
 import io.gravitee.rest.api.model.permissions.SystemRole;
 import io.gravitee.rest.api.model.v4.api.GenericApiModel;
@@ -40,6 +42,7 @@
 import io.gravitee.rest.api.service.notification.PortalHook;
 import io.gravitee.rest.api.service.v4.ApiTemplateService;
 import java.util.*;
+import java.util.function.Predicate;
 import java.util.stream.Collectors;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -111,6 +114,9 @@ public class MessageServiceImpl extends AbstractService implements MessageServic
     @Autowired
     private Environment environment;
 
+    @Autowired
+    private ParameterService parameterService;
+
     private List<String> httpWhitelist;
 
     @Override
@@ -345,13 +351,16 @@ private Set<String> getRecipientsEmails(ExecutionContext executionContext, Set<S
             return Collections.emptySet();
         }
 
-        Set<String> emails = userService
+        final boolean isTrialInstance = parameterService.findAsBoolean(executionContext, Key.TRIAL_INSTANCE, ParameterReferenceType.SYSTEM);
+        final Predicate<UserEntity> excludeIfTrialAndNotOptedIn = userEntity -> !isTrialInstance || userEntity.optedIn();
+
+        return userService
             .findByIds(executionContext, new ArrayList<>(recipientsId))
             .stream()
             .filter(userEntity -> !StringUtils.isEmpty(userEntity.getEmail()))
+            .filter(excludeIfTrialAndNotOptedIn)
             .map(UserEntity::getEmail)
             .collect(Collectors.toSet());
-        return emails;
     }
 
     private void assertMessageNotEmpty(MessageEntity messageEntity) {