diff --git a/config/env.example.optional b/config/env.example.optional
index d24484809..94b3b616b 100644
--- a/config/env.example.optional
+++ b/config/env.example.optional
@@ -236,4 +236,7 @@ DS_LOG_LEVEL='info'
 # Admins group usage (gestionnaire de groupes d'administrateurs)
 # can be removed if needed when EVERY PARTS of the feature will be merged / only used in routes.rb
 ADMINS_GROUP_ENABLED="disabled"
+
+# Do you want to isolate bulk email (notifications) from transactional ones (ex: reset password).
+# BULK_EMAIL_QUEUE will host bulk email (notifications)
 BULK_EMAIL_QUEUE="low_priority"