diff --git a/bundles/postfix/files/main.cf b/bundles/postfix/files/main.cf
index 7c944aa..e0a3952 100644
--- a/bundles/postfix/files/main.cf
+++ b/bundles/postfix/files/main.cf
@@ -1,6 +1,7 @@
 smtpd_banner = $myhostname ESMTP
 
 disable_vrfy_command = yes
+smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, defer_unauth_destination
 
 smtp_use_tls = yes
 smtp_tls_CApath = /etc/pki/tls/certs