diff --git a/bundles/mailserver/metadata.py b/bundles/mailserver/metadata.py
index bc82537..69388f4 100644
--- a/bundles/mailserver/metadata.py
+++ b/bundles/mailserver/metadata.py
@@ -82,6 +82,7 @@ def dns(metadata):
         'dns': dns,
     }
 
+
 @metadata_reactor.provides(
     'letsencrypt/domains',
 )
diff --git a/hooks/test_ptr_records.py b/hooks/test_ptr_records.py
new file mode 100644
index 0000000..cbccf50
--- /dev/null
+++ b/hooks/test_ptr_records.py
@@ -0,0 +1,18 @@
+from subprocess import check_output
+
+
+def test_node(repo, node, **kwargs):
+    for node in repo.nodes_in_group('mailserver'):
+        domain = node.metadata.get('mailserver/hostname')
+        expected_ptr_record = f"{domain}."
+        expected_a_record = node.hostname
+
+        # check A record
+        actual_a_record = check_output(['dig', '+short', 'A', domain, '@9.9.9.9'], text=True).strip()
+        if actual_a_record != expected_a_record:
+            raise AssertionError(f"A record for {expected_a_record} on node {node.name} is {actual_a_record}, expected {expected_a_record}")
+
+        # check otr record
+        actual_ptr_record = check_output(['dig', '+short', '-x', expected_a_record, '@9.9.9.9'], text=True).strip()
+        if actual_ptr_record != expected_ptr_record:
+            raise AssertionError(f"PTR record for {expected_a_record} on node {node.name} is {actual_ptr_record}, expected {expected_ptr_record}")