diff --git a/.env b/.env
index 99cd9380..4a853b35 100644
--- a/.env
+++ b/.env
@@ -36,7 +36,7 @@ CORS_ALLOW_ORIGIN=^https?://(get\.typo3\.org)(:[0-9]+)?$
 ###< nelmio/cors-bundle ###
 
 ###> symfony/mailer ###
-# MAILER_DSN=smtp://localhost
+MAILER_DSN=null://null
 ###< symfony/mailer ###
 
 # todo: reduce to APP_DOMAIN
diff --git a/symfony.lock b/symfony.lock
index 358a2627..421d3a53 100644
--- a/symfony.lock
+++ b/symfony.lock
@@ -394,12 +394,12 @@
         "version": "v5.1.9"
     },
     "symfony/mailer": {
-        "version": "4.3",
+        "version": "6.4",
         "recipe": {
             "repo": "github.com/symfony/recipes",
-            "branch": "master",
+            "branch": "main",
             "version": "4.3",
-            "ref": "15658c2a0176cda2e7dba66276a2030b52bd81b2"
+            "ref": "09051cfde49476e3c12cd3a0e44289ace1c75a4f"
         },
         "files": [
             "config/packages/mailer.yaml"