feat: pause campaign batches on SMTP failure

tests/test_sending_jobs.py

@@ -2,7 +2,7 @@ from __future__ import annotations
 
 import unittest
 from types import SimpleNamespace
-from unittest.mock import patch
+from unittest.mock import ANY, patch
 
 from govoplan_campaign.backend.db.models import (
     JobBuildStatus,
@@ -17,6 +17,7 @@ from govoplan_campaign.backend.sending.jobs import (
     _select_campaign_jobs_for_queue,
     _send_claimed_campaign_job,
 )
+from govoplan_campaign.backend.integrations import SmtpSendError
 
 
 class FakeSession:
@@ -220,6 +221,62 @@ class CampaignQueueSelectionTests(unittest.TestCase):
         self.assertTrue(session.rolled_back)
         self.assertIn("Automatic retry is stopped", mark_unknown.call_args.kwargs["reason"])
 
+    def test_systemic_smtp_failure_pauses_remaining_campaign_jobs(self):
+        job = SimpleNamespace(
+            id="job-1",
+            tenant_id="tenant-1",
+            campaign_id="campaign-1",
+            campaign_version_id="version-1",
+            delivery_channel_policy="mail",
+            resolved_recipients={"from": {"email": "sender@example.test"}},
+        )
+        context = SimpleNamespace(
+            snapshot=SimpleNamespace(
+                mail_profile_id="profile-1",
+                smtp_server_id=None,
+                smtp_credential_id=None,
+                smtp_transport_revision="revision-1",
+                delivery=SimpleNamespace(rate_limit=SimpleNamespace(messages_per_minute=60)),
+            ),
+            message_bytes=b"message",
+            envelope_from="sender@example.test",
+            envelope_recipients=["recipient@example.test"],
+        )
+
+        class Mail:
+            def wait_for_rate_limit(self, **_kwargs):
+                return None
+
+            def send_campaign_email_bytes(self, *_args, **_kwargs):
+                raise SmtpSendError(
+                    "SMTP authentication failed.",
+                    systemic=True,
+                    reason_code="smtp_authentication_failed",
+                )
+
+        with (
+            patch("govoplan_campaign.backend.sending.jobs.mail_integration", return_value=Mail()),
+            patch("govoplan_campaign.backend.sending.jobs._record_attempt_start", return_value=SimpleNamespace(attempt_number=1)),
+            patch("govoplan_campaign.backend.sending.jobs._record_smtp_send_error", return_value=None),
+            patch("govoplan_campaign.backend.sending.jobs._pause_jobs_after_systemic_smtp_failure", return_value=4) as pause,
+            self.assertRaises(SmtpSendError),
+        ):
+            _send_claimed_campaign_job(
+                object(),  # type: ignore[arg-type]
+                job=job,  # type: ignore[arg-type]
+                claim_token="claim-1",
+                context=context,  # type: ignore[arg-type]
+                use_rate_limit=False,
+                enqueue_imap_task=False,
+            )
+
+        pause.assert_called_once_with(
+            ANY,
+            campaign_id="campaign-1",
+            exclude_job_id="job-1",
+            reason_code="smtp_authentication_failed",
+        )
+
 
 if __name__ == "__main__":
     unittest.main()