diff --git a/config/env.example b/config/env.example
index a3624b572..1bf29b439 100644
--- a/config/env.example
+++ b/config/env.example
@@ -155,3 +155,10 @@ CLAMAV_ENABLED="disabled"
 
 # Siret number used for API Entreprise, by default we use SIRET from dinum
 API_ENTREPRISE_DEFAULT_SIRET="put_your_own_siret"
+
+# Date from which email validation requires a TLD in email adresses.
+# This change had been introduced by : cc53946d221d6f64c365ad6c6c4c544802eb94b4
+# Records (users, …) created before this date won't be affected. See #9978
+# To set a date, we recommend using *the day after* you have deployed this commit,
+# so existing records won't be invalid.
+STRICT_EMAIL_VALIDATION_STARTS_ON="2024-02-19"