Re-enable test_check_smtp_pool test

Story: #2000773

Change-Id: I66a813b133b8c594e5d46f31f3add114708d8063
Signed-off-by: Paul Belanger <pabelanger@redhat.com>
diff --git a/tests/fixtures/config/single-tenant/git/layout-smtp/zuul.yaml b/tests/fixtures/config/single-tenant/git/layout-smtp/zuul.yaml
new file mode 100644
index 0000000..9effb1f
--- /dev/null
+++ b/tests/fixtures/config/single-tenant/git/layout-smtp/zuul.yaml
@@ -0,0 +1,81 @@
+- pipeline:
+    name: check
+    manager: independent
+    source:
+      gerrit
+    trigger:
+      gerrit:
+        - event: patchset-created
+    start:
+      smtp:
+        to: you@example.com
+    success:
+      gerrit:
+        verified: 1
+      smtp:
+        to: alternative_me@example.com
+        from: zuul_from@example.com
+    failure:
+      gerrit:
+        verified: -1
+
+- pipeline:
+    name: gate
+    manager: dependent
+    success-message: Build succeeded (gate).
+    source:
+      gerrit
+    trigger:
+      gerrit:
+        - event: comment-added
+          approval:
+            - approved: 1
+    success:
+      gerrit:
+        verified: 2
+        submit: true
+    failure:
+      gerrit:
+        verified: -2
+    start:
+      gerrit:
+        verified: 0
+    precedence: high
+
+- job:
+    name: project-merge
+    hold-following-changes: true
+
+- job:
+    name: project-test1
+    nodes:
+      - name: controller
+        image: image1
+
+- job:
+    name: project-test1
+    branches: stable
+    nodes:
+      - name: controller
+        image: image2
+
+- job:
+    name: project-test2
+
+- job:
+    name: experimental-project-test
+
+- project:
+    name: org/project
+    check:
+      jobs:
+        - project-merge:
+            jobs:
+              - project-test1
+              - project-test2
+    gate:
+      jobs:
+        - project-merge:
+            jobs:
+              - project-test1
+              - project-test2
diff --git a/tests/test_scheduler.py b/tests/test_scheduler.py
index 5b97e53..e24c72a 100755
--- a/tests/test_scheduler.py
+++ b/tests/test_scheduler.py
@@ -3003,10 +3003,8 @@
             self.assertEqual(len(self.builds), 0)
             self.assertEqual(len(self.history), x * 2)
 
-    @skip("Disabled for early v3 development")
     def test_check_smtp_pool(self):
-        self.updateConfigLayout(
-            'tests/fixtures/layout-smtp.yaml')
+        self.updateConfigLayout('layout-smtp')
         self.sched.reconfigure(self.config)
 
         A = self.fake_gerrit.addFakeChange('org/project', 'master', 'A')