diff --git a/lib/Providers/Mail/Provider.php b/lib/Providers/Mail/Provider.php
index af454b5..be16ee3 100644
--- a/lib/Providers/Mail/Provider.php
+++ b/lib/Providers/Mail/Provider.php
@@ -142,7 +142,7 @@ class Provider implements ProviderBaseInterface, ProviderServiceMutateInterface,
         }
 
         $created = $this->serviceStore->create($tenantId, $userId, $service);
-        return (string) $created['id'];
+        return (string) $created['sid'];
     }
 
     public function serviceModify(string $tenantId, string $userId, ResourceServiceMutateInterface $service): string
@@ -151,8 +151,8 @@ class Provider implements ProviderBaseInterface, ProviderServiceMutateInterface,
             throw new \InvalidArgumentException('Service must be instance of JMAP Service');
         }
 
-        $updated = $this->serviceStore->modify($tenantId, $userId, $service);
-        return (string) $updated['sid'];
+        $this->serviceStore->modify($tenantId, $userId, $service);
+        return (string) $service->identifier();
     }
 
     public function serviceDestroy(string $tenantId, string $userId, ResourceServiceMutateInterface $service): bool