diff --git a/target/start-mailserver.sh b/target/start-mailserver.sh
index 2dd25a02..d085a4b1 100644
--- a/target/start-mailserver.sh
+++ b/target/start-mailserver.sh
@@ -122,6 +122,7 @@ function register_functions() {
 	_register_setup_function "_setup_postfix_hostname"
 	_register_setup_function "_setup_dovecot_hostname"
 
+	_register_setup_function "_setup_postfix_smtputf8"
 	_register_setup_function "_setup_postfix_sasl"
 	_register_setup_function "_setup_postfix_override_configuration"
 	_register_setup_function "_setup_postfix_sasl_password"
@@ -706,6 +707,11 @@ function _setup_postfix_sizelimits() {
 	postconf -e "mailbox_size_limit = ${DEFAULT_VARS["POSTFIX_MAILBOX_SIZE_LIMIT"]}"
 }
 
+function _setup_postfix_smtputf8() {
+        notify 'inf' "Configuring postfix smtputf8 support (disable)"
+        postconf -e "smtputf8_enable = no"
+}
+
 function _setup_spoof_protection () {
 	notify 'inf' "Configuring Spoof Protection"
 	sed -i 's|smtpd_sender_restrictions =|smtpd_sender_restrictions = reject_authenticated_sender_login_mismatch,|' /etc/postfix/main.cf
diff --git a/test/test-files/email-templates/smtp-ehlo.txt b/test/test-files/email-templates/smtp-ehlo.txt
new file mode 100644
index 00000000..05524efd
--- /dev/null
+++ b/test/test-files/email-templates/smtp-ehlo.txt
@@ -0,0 +1,2 @@
+EHLO mail.localhost
+QUIT
diff --git a/test/tests.bats b/test/tests.bats
index e65e6693..1c29f86e 100644
--- a/test/tests.bats
+++ b/test/tests.bats
@@ -405,6 +405,14 @@ function count_processed_changes() {
   [ "$status" -ge 0 ]
 }
 
+@test "checking smtp: not advertising smtputf8" {
+  # Dovecot does not support SMTPUTF8, so while we can send we cannot receive
+  # Better disable SMTPUTF8 support entirely if we can't handle it correctly
+  run docker exec mail /bin/sh -c "nc 0.0.0.0 25 < /tmp/docker-mailserver-test/email-templates/smtp-ehlo.txt | grep SMTPUTF8 | wc -l"
+  assert_success
+  assert_output 0
+}
+
 #
 # accounts
 #