diff --git a/install/tpl/debian_postfix.conf.master b/install/tpl/debian_postfix.conf.master
index 9a623c264e7b7c1908ad1fe21b4a2a7a5bc78e28..8a1b0fc4fce37770ae275f4e4613c4e9ce336587 100644
--- a/install/tpl/debian_postfix.conf.master
+++ b/install/tpl/debian_postfix.conf.master
@@ -29,6 +29,7 @@ smtpd_helo_required = yes
 smtpd_helo_restrictions = permit_sasl_authenticated, permit_mynetworks, check_helo_access regexp:{config_dir}/helo_access, reject_non_fqdn_helo_hostname, reject_invalid_helo_hostname, reject_unknown_helo_hostname, check_helo_access regexp:{config_dir}/blacklist_helo
 smtpd_sender_restrictions = check_sender_access regexp:{config_dir}/tag_as_originating.re {reject_slm}, permit_mynetworks, permit_sasl_authenticated, check_sender_access mysql:{config_dir}/mysql-virtual_sender.cf, check_sender_access regexp:{config_dir}/tag_as_foreign.re
 smtpd_client_restrictions = check_client_access mysql:{config_dir}/mysql-virtual_client.cf
+smtpd_etrn_restrictions = permit_mynetworks, reject
 smtpd_data_restrictions = reject_unauth_pipelining, reject_multi_recipient_bounce, permit
 smtpd_client_message_rate_limit = 100
 maildrop_destination_concurrency_limit = 1
diff --git a/install/tpl/fedora_postfix.conf.master b/install/tpl/fedora_postfix.conf.master
index 02603275791250f56d76621d7f54d5af70ee30b7..b3e79478d23a75820ebdd4a64ecb2d38de486d15 100644
--- a/install/tpl/fedora_postfix.conf.master
+++ b/install/tpl/fedora_postfix.conf.master
@@ -25,6 +25,7 @@ smtpd_helo_required = yes
 smtpd_helo_restrictions = permit_sasl_authenticated, permit_mynetworks, check_helo_access regexp:{config_dir}/helo_access, reject_non_fqdn_helo_hostname, reject_invalid_helo_hostname, reject_unknown_helo_hostname, check_helo_access regexp:{config_dir}/blacklist_helo
 smtpd_sender_restrictions = check_sender_access regexp:{config_dir}/tag_as_originating.re {reject_slm}, permit_mynetworks, permit_sasl_authenticated, check_sender_access mysql:{config_dir}/mysql-virtual_sender.cf, check_sender_access regexp:{config_dir}/tag_as_foreign.re
 smtpd_client_restrictions = check_client_access mysql:{config_dir}/mysql-virtual_client.cf
+smtpd_etrn_restrictions = permit_mynetworks, reject
 smtpd_data_restrictions = reject_unauth_pipelining, reject_multi_recipient_bounce, permit
 smtpd_client_message_rate_limit = 100
 maildrop_destination_concurrency_limit = 1
diff --git a/install/tpl/gentoo_postfix.conf.master b/install/tpl/gentoo_postfix.conf.master
index a589bb0dac6ebbb12843a1347533ae5f4c9a44a0..0dde56c4a1bae048ace165abdfd0d4727f5574e6 100644
--- a/install/tpl/gentoo_postfix.conf.master
+++ b/install/tpl/gentoo_postfix.conf.master
@@ -24,6 +24,7 @@ smtpd_helo_required = yes
 smtpd_helo_restrictions = permit_sasl_authenticated, permit_mynetworks, check_helo_access regexp:{config_dir}/helo_access, reject_non_fqdn_hostname, reject_invalid_helo_hostname, reject_unknown_helo_hostname, check_helo_access regexp:{config_dir}/blacklist_helo
 smtpd_sender_restrictions = check_sender_access regexp:{config_dir}/tag_as_originating.re {reject_slm}, permit_mynetworks, permit_sasl_authenticated, check_sender_access mysql:{config_dir}/mysql-virtual_sender.cf, check_sender_access regexp:{config_dir}/tag_as_foreign.re
 smtpd_client_restrictions = check_client_access mysql:{config_dir}/mysql-virtual_client.cf
+smtpd_etrn_restrictions = permit_mynetworks, reject
 smtpd_data_restrictions = reject_unauth_pipelining, reject_multi_recipient_bounce, permit
 smtpd_client_message_rate_limit = 100
 maildrop_destination_concurrency_limit = 1
diff --git a/install/tpl/opensuse_postfix.conf.master b/install/tpl/opensuse_postfix.conf.master
index 4eea85154aeec8e047869a9ec42473ca0321a701..08ed58d861df1b20fe33bf7982bd0a2fc9405d42 100644
--- a/install/tpl/opensuse_postfix.conf.master
+++ b/install/tpl/opensuse_postfix.conf.master
@@ -27,6 +27,7 @@ smtpd_helo_required = yes
 smtpd_helo_restrictions = permit_sasl_authenticated, permit_mynetworks, check_helo_access regexp:{config_dir}/helo_access, reject_non_fqdn_helo_hostname, reject_invalid_helo_hostname, reject_unknown_helo_hostname, check_helo_access regexp:{config_dir}/blacklist_helo
 smtpd_sender_restrictions = check_sender_access regexp:{config_dir}/tag_as_originating.re {reject_slm}, permit_mynetworks, permit_sasl_authenticated, check_sender_access mysql:{config_dir}/mysql-virtual_sender.cf, check_sender_access regexp:{config_dir}/tag_as_foreign.re
 smtpd_client_restrictions = check_client_access mysql:{config_dir}/mysql-virtual_client.cf
+smtpd_etrn_restrictions = permit_mynetworks, reject
 smtpd_data_restrictions = reject_unauth_pipelining, reject_multi_recipient_bounce, permit
 smtpd_client_message_rate_limit = 100
 maildrop_destination_concurrency_limit = 1