diff --git a/data/templates/postfix/main.cf b/data/templates/postfix/main.cf
index a6982d848..045b8edd0 100644
--- a/data/templates/postfix/main.cf
+++ b/data/templates/postfix/main.cf
@@ -159,8 +159,12 @@ smtpd_milters = inet:localhost:11332
 # Skip email without checking if milter has died
 milter_default_action = accept
 
+# Avoid to send simultaneously too many emails
+smtp_destination_concurrency_limit = 1
+default_destination_rate_delay = 5s
+
 # Avoid email adress scanning
 # By default it's possible to detect if the email adress exist
 # So it's easly possible to scan a server to know which email adress is valid
 # and after to send spam
-disable_vrfy_command = yes
+disable_vrfy_command = yes
\ No newline at end of file