diff --git a/data/templates/postfix/main.cf b/data/templates/postfix/main.cf
index c38896a3f..aea68cd28 100644
--- a/data/templates/postfix/main.cf
+++ b/data/templates/postfix/main.cf
@@ -154,3 +154,7 @@ smtpd_milters = inet:localhost:11332
 
 # Skip email without checking if milter has died
 milter_default_action = accept
+
+# Avoid to send simultaneously too much emails
+smtp_destination_concurrency_limit = 1
+default_destination_rate_delay = 12s