refs #73086 changed the smtp_tls_security_level to encrypt

docker-setup.sh

@@ -8,7 +8,7 @@ function setup_conf_and_secret {
     postconf -e 'smtp_sasl_auth_enable = yes'
     postconf -e 'smtp_sasl_password_maps = hash:/etc/postfix/relay_passwd'
     postconf -e 'smtp_sasl_security_options = noanonymous'
-    postconf -e 'smtp_tls_security_level = may'
+    postconf -e 'smtp_tls_security_level = encrypt'
     postconf -e 'mynetworks = 127.0.0.0/8 172.17.0.0/16 10.42.0.0/16'
 
     echo "$MTP_RELAY   $MTP_USER:$MTP_PASS" > /etc/postfix/relay_passwd