diff --git a/templates/Fedora/35/etc/postfix/main.cf b/templates/Fedora/35/etc/postfix/main.cf
index b3d981a..5b19283 100644
--- a/templates/Fedora/35/etc/postfix/main.cf
+++ b/templates/Fedora/35/etc/postfix/main.cf
@@ -760,4 +760,6 @@ error_notice_recipient = {{ postmaster_email }}
 smtpd_helo_required = yes
 disable_vrfy_command = yes
 message_size_limit = {{ postfix_message_size_limit }}
+smtpd_helo_restrictions = reject_unknown_helo_hostname
+smtpd_client_restrictions = reject_unknown_reverse_client_hostname reject_unauth_pipelining
 
diff --git a/templates/Fedora/36/etc/postfix/main.cf b/templates/Fedora/36/etc/postfix/main.cf
index b3d981a..5b19283 100644
--- a/templates/Fedora/36/etc/postfix/main.cf
+++ b/templates/Fedora/36/etc/postfix/main.cf
@@ -760,4 +760,6 @@ error_notice_recipient = {{ postmaster_email }}
 smtpd_helo_required = yes
 disable_vrfy_command = yes
 message_size_limit = {{ postfix_message_size_limit }}
+smtpd_helo_restrictions = reject_unknown_helo_hostname
+smtpd_client_restrictions = reject_unknown_reverse_client_hostname reject_unauth_pipelining