diff --git a/tasks/main.yml b/tasks/main.yml
index 972bce7..f39c431 100644
--- a/tasks/main.yml
+++ b/tasks/main.yml
@@ -34,7 +34,9 @@
   ansible.builtin.include_tasks: mta-sts.yml
   tags: mta-sts
   loop: "{{ postfix_domains }}"
-  when: postfix_domains is defined
+  when:
+    - postfix_domains is defined
+    - postfix_type == "internet"
   args:
     apply:
       delegate_to: "{{ gateway_host }}"