diff --git a/src/Bundle/ChillCalendarBundle/RemoteCalendar/Connector/MSGraph/MapCalendarToUser.php b/src/Bundle/ChillCalendarBundle/RemoteCalendar/Connector/MSGraph/MapCalendarToUser.php
index 158982fdd..7e7d55739 100644
--- a/src/Bundle/ChillCalendarBundle/RemoteCalendar/Connector/MSGraph/MapCalendarToUser.php
+++ b/src/Bundle/ChillCalendarBundle/RemoteCalendar/Connector/MSGraph/MapCalendarToUser.php
@@ -130,6 +130,10 @@ class MapCalendarToUser
 
     public function hasUserId(User $user): bool
     {
+        if (null === $user->getEmail() || '' === $user->getEmail()) {
+            return false;
+        }
+
         if (!array_key_exists(self::METADATA_KEY, $user->getAttributes())) {
             return false;
         }
@@ -139,6 +143,10 @@ class MapCalendarToUser
 
     public function writeMetadata(User $user): User
     {
+        if (null === $user->getEmail() OR '' === $user->getEmail()) {
+            return $user;
+        }
+
         if (null === $userData = $this->getUserByEmail($user->getEmailCanonical())) {
             $this->logger->warning('[MapCalendarToUser] could not find user on msgraph', ['userId' => $user->getId(), 'email' => $user->getEmailCanonical()]);