diff --git a/site-cookbooks/kosmos_email/recipes/postfix.rb b/site-cookbooks/kosmos_email/recipes/postfix.rb
index ef1b9e4..6d6d18e 100644
--- a/site-cookbooks/kosmos_email/recipes/postfix.rb
+++ b/site-cookbooks/kosmos_email/recipes/postfix.rb
@@ -78,6 +78,7 @@ node.normal['postfix']['master'] = {
       "-o syslog_name=postfix/10465",
       "-o smtpd_tls_wrappermode=yes",
       "-o smtpd_sasl_auth_enable=yes",
+      "-o smtpd_relay_restrictions=permit_sasl_authenticated,reject",
       "-o smtpd_recipient_restrictions=permit_mynetworks,permit_sasl_authenticated,reject",
       "-o smtpd_sasl_type=dovecot",
       "-o smtpd_sasl_path=private/auth",