feat: start mailbox evidence scanner

tests/fixtures/mailbox/hard_bounce.eml

@@ -0,0 +1,12 @@
+From: Mail Delivery Subsystem <mailer-daemon@example.net>
+To: sender@example.com
+Subject: Delivery Status Notification (Failure)
+Date: Tue, 02 Jun 2026 10:00:00 +0000
+Message-ID: <hard-bounce@example.net>
+Content-Type: text/plain; charset=utf-8
+
+Delivery failure.
+Final-Recipient: rfc822; missing@example.com
+Action: failed
+Status: 5.1.1
+Diagnostic-Code: smtp; 550 5.1.1 User unknown

tests/fixtures/mailbox/human_reply.eml

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+From: Recipient <recipient@example.com>
+To: sender@example.com
+Subject: Re: Your notification
+Date: Tue, 02 Jun 2026 10:03:00 +0000
+Message-ID: <reply@example.com>
+Content-Type: text/plain; charset=utf-8
+
+Thanks, I received this and will review it today.

tests/fixtures/mailbox/out_of_office.eml

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+From: Recipient <recipient@example.com>
+To: sender@example.com
+Subject: Auto-reply: Out of office
+Date: Tue, 02 Jun 2026 10:02:00 +0000
+Message-ID: <ooo@example.com>
+Auto-Submitted: auto-replied
+Content-Type: text/plain; charset=utf-8
+
+I am out of office until next week.

tests/fixtures/mailbox/soft_bounce.eml

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+From: Mail Delivery Subsystem <mailer-daemon@example.net>
+To: sender@example.com
+Subject: Delivery temporarily delayed
+Date: Tue, 02 Jun 2026 10:01:00 +0000
+Message-ID: <soft-bounce@example.net>
+Content-Type: text/plain; charset=utf-8
+
+Delivery Status Notification.
+Final-Recipient: rfc822; full@example.com
+Action: delayed
+Status: 4.2.2
+Diagnostic-Code: smtp; 452 4.2.2 Mailbox full

tests/test_parser.py

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+from __future__ import annotations
+
+import unittest
+from pathlib import Path
+
+from email_connect.models import MessageClass
+from email_connect.parser import parse_message_file
+
+
+FIXTURES = Path(__file__).parent / "fixtures" / "mailbox"
+
+
+class ParserTests(unittest.TestCase):
+    def test_hard_bounce_maps_to_permanent_rejection(self) -> None:
+        _inbound, parsed, candidate = parse_message_file(FIXTURES / "hard_bounce.eml", mailbox_id="test")
+        self.assertEqual(parsed.message_class, MessageClass.HARD_BOUNCE)
+        self.assertIsNotNone(candidate)
+        self.assertEqual(candidate.event_type, "notification.endpoint.rejected_permanent")
+        self.assertEqual(candidate.assessment_subclass, "fail.hard_bounce")
+
+    def test_soft_bounce_maps_to_temporary_rejection(self) -> None:
+        _inbound, parsed, candidate = parse_message_file(FIXTURES / "soft_bounce.eml", mailbox_id="test")
+        self.assertEqual(parsed.message_class, MessageClass.SOFT_BOUNCE)
+        self.assertIsNotNone(candidate)
+        self.assertEqual(candidate.event_type, "notification.endpoint.rejected_temporary")
+
+    def test_out_of_office_stays_undef(self) -> None:
+        _inbound, parsed, candidate = parse_message_file(FIXTURES / "out_of_office.eml", mailbox_id="test")
+        self.assertEqual(parsed.message_class, MessageClass.OUT_OF_OFFICE)
+        self.assertIsNotNone(candidate)
+        self.assertEqual(candidate.assessment_category.value, "undef")
+        self.assertEqual(candidate.event_type, "interaction.out_of_office_received")
+
+    def test_human_reply_is_email_channel_success_only(self) -> None:
+        _inbound, parsed, candidate = parse_message_file(FIXTURES / "human_reply.eml", mailbox_id="test")
+        self.assertEqual(parsed.message_class, MessageClass.HUMAN_REPLY)
+        self.assertIsNotNone(candidate)
+        self.assertEqual(candidate.event_type, "interaction.reply_received")
+        self.assertEqual(candidate.assessment_subclass, "success.reply_received")
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_scanner.py

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+from __future__ import annotations
+
+import tempfile
+import unittest
+from pathlib import Path
+
+from email_connect.config import AppConfig, MailboxConfig, ReportsConfig, ScanConfig, SourceConfig, StorageConfig
+from email_connect.scanner import scan_mailbox
+
+
+FIXTURES = Path(__file__).parent / "fixtures" / "mailbox"
+
+
+class ScannerTests(unittest.TestCase):
+    def test_scan_fixture_directory_writes_report_and_deduplicates(self) -> None:
+        with tempfile.TemporaryDirectory() as tmp:
+            root = Path(tmp)
+            config = AppConfig(
+                mailbox=MailboxConfig(id="test-mailbox", protocol="fixture"),
+                scan=ScanConfig(),
+                storage=StorageConfig(path=str(root / "state.sqlite")),
+                reports=ReportsConfig(output_dir=str(root / "reports")),
+                source=SourceConfig(fixture_dir=str(FIXTURES)),
+            )
+            first = scan_mailbox(config)
+            second = scan_mailbox(config)
+
+            self.assertEqual(first.scan.messages_seen, 4)
+            self.assertEqual(first.scan.messages_new, 4)
+            self.assertGreaterEqual(first.scan.evidence_events_created, 4)
+            self.assertEqual(second.scan.messages_new, 0)
+            self.assertEqual(second.scan.evidence_events_created, 0)
+            self.assertTrue(first.report_path and first.report_path.exists())
+
+
+if __name__ == "__main__":
+    unittest.main()