diff --git a/configurator/src/Configurator/Vendor/Keycloak/KeycloakConfigurator.php b/configurator/src/Configurator/Vendor/Keycloak/KeycloakConfigurator.php
index c4c097a91..a81e477e6 100644
--- a/configurator/src/Configurator/Vendor/Keycloak/KeycloakConfigurator.php
+++ b/configurator/src/Configurator/Vendor/Keycloak/KeycloakConfigurator.php
@@ -193,7 +193,7 @@ private function configureRealm(): void
                 'from' => $from,
                 'fromDisplayName' => 'Phrasea',
                 'host' => $mailer['host'],
-                'port' => $mailer['port'],
+                'port' => $mailer['port'] ?? '587',
                 'replyTo' => '',
                 'ssl' => false,
                 'starttls' => false,