Antispam: never classify during backfill

message.new fires for imported history as well as new arrivals, and EventBus
awaits hooks inline. As written, adding an account would have scored every
message in its backfill — filing years-old inbox mail into Junk on the server,
and adding ~70 ms of serialized HTTP per message to the backfill loop (twelve
minutes on a 10k-message account). It is also when the filter is least able to
judge, because Bayes has learned nothing yet.

The envelope now carries account_state, and the hook returns unless it is
"live". The backfill window belongs to the C2 learning bootstrap (§C.5), which
reads that history as training data instead of acting on it.

Tests pin the gating: backfilling accounts are not even read from the blob
store, non-inbox folders are ignored, a live inbox arrival still classifies, and
an unreachable engine still delivers.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018SqJYt7jD7oUEkoY68sBZo
This commit is contained in:
2026-09-17 07:59:15 +02:00
co-authored by Claude Opus 5
parent c3ae613bf4
commit dee1983b84
3 changed files with 156 additions and 3 deletions
+8 -3
View File
@@ -23,7 +23,7 @@ from sqlalchemy import select
from app.db import session_scope
from app.events import get_event_bus
from app.indexer import blobstore
from app.models import Mailbox, Message, Thread
from app.models import Account, Mailbox, Message, Thread
class PluginMessages:
@@ -92,14 +92,15 @@ class PluginMessages:
async with session_scope() as session:
row = (
await session.execute(
select(Message, Mailbox.special_use)
select(Message, Mailbox.special_use, Account.state)
.join(Mailbox, Mailbox.id == Message.mailbox_id, isouter=True)
.join(Account, Account.id == Message.account_id, isouter=True)
.where(Message.id == message_id, Message.user_id == user_id)
)
).first()
if row is None:
return None
msg, special_use = row
msg, special_use, account_state = row
sender = msg.from_addr[0] if msg.from_addr else {}
return {
"message_id": str(msg.id),
@@ -108,6 +109,10 @@ class PluginMessages:
# with no SPECIAL-USE. A plugin that should only act on newly
# arrived mail checks this — `message.new` itself does not say.
"mailbox_special_use": special_use,
# "backfilling" | "live" | … — `message.new` fires for imported
# history too, so a plugin that should only react to genuinely
# new arrivals has to be able to tell the difference.
"account_state": account_state,
"subject": msg.subject or "",
"from_email": (sender.get("email") or "").lower(),
"from_name": sender.get("name") or "",
@@ -0,0 +1,138 @@
"""What the antispam hook refuses to touch (SPEC §C.4).
The gating matters more than the scoring: `message.new` fires for imported
history and for every folder, so a hook that acts on all of it would file
years-old mail into Junk and stall backfill with inline HTTP.
"""
from __future__ import annotations
import uuid
from typing import Any
import pytest
from webmail_plugin_antispam import hook, policy
LIVE_INBOX = {
"message_id": "m",
"account_id": "acc-1",
"mailbox_special_use": "inbox",
"account_state": "live",
"from_email": "someone@example.test",
"subject": "hello",
"to": [],
"flags": [],
}
class _FakeMessages:
def __init__(self, env: dict[str, Any] | None) -> None:
self._env = env
self.raw_calls = 0
async def envelope(self, *_a: object, **_k: object) -> dict[str, Any] | None:
return self._env
async def raw(self, *_a: object, **_k: object) -> bytes | None:
self.raw_calls += 1
return b"From: someone@example.test\r\n\r\nbody\r\n"
class _FakeActions:
def __init__(self) -> None:
self.moves: list[str] = []
async def move_to_special(self, _u: object, _m: object, special_use: str) -> bool:
self.moves.append(special_use)
return True
class _FakeSdk:
def __init__(self, env: dict[str, Any] | None) -> None:
self.messages = _FakeMessages(env)
self.actions = _FakeActions()
self.published: list[tuple[str, dict[str, Any]]] = []
async def publish(self, event: str, payload: dict[str, Any]) -> None:
self.published.append((event, payload))
@pytest.fixture
def wired(monkeypatch: pytest.MonkeyPatch): # type: ignore[no-untyped-def]
"""Swap the hook's SDK and its database/engine calls for fakes."""
recorded: list[dict[str, Any]] = []
async def _record(_u: object, _m: object, **kw: Any) -> None:
recorded.append(kw)
async def _settings(_u: object) -> policy.Settings:
return policy.Settings(
enabled_accounts=[],
move_threshold=12.0,
banner_threshold=6.0,
network_checks=False,
learn_from_provider_junk=True,
)
async def _rules(_u: object) -> dict[str, set[str]]:
return {"allow": set(), "deny": set()}
monkeypatch.setattr(hook, "_record", _record)
monkeypatch.setattr(policy, "load_settings", _settings)
monkeypatch.setattr(policy, "load_rules", _rules)
def _install(env: dict[str, Any] | None, score: float | None = None) -> _FakeSdk:
fake = _FakeSdk(env)
monkeypatch.setattr(hook, "_SDK", fake)
async def _check(*_a: object, **_k: object) -> object:
if score is None:
return None
return type("V", (), {"score": score, "symbols": ["X"]})()
monkeypatch.setattr(hook.rspamd, "check", _check)
return fake
return _install, recorded
async def _fire() -> None:
await hook.on_message_new({"user_id": str(uuid.uuid4()), "message_id": str(uuid.uuid4())})
async def test_skips_while_the_account_is_backfilling(wired) -> None: # type: ignore[no-untyped-def]
"""Imported history must not be scored, moved, or slowed down."""
install, recorded = wired
fake = install({**LIVE_INBOX, "account_state": "backfilling"}, score=99.0)
await _fire()
assert fake.messages.raw_calls == 0 # never even fetched the body
assert fake.actions.moves == []
assert recorded == []
@pytest.mark.parametrize("special_use", ["sent", "junk", "trash", "drafts", None])
async def test_skips_everything_outside_the_inbox(wired, special_use) -> None: # type: ignore[no-untyped-def]
install, recorded = wired
fake = install({**LIVE_INBOX, "mailbox_special_use": special_use}, score=99.0)
await _fire()
assert fake.actions.moves == []
assert recorded == []
async def test_classifies_a_live_inbox_arrival(wired) -> None: # type: ignore[no-untyped-def]
install, recorded = wired
fake = install(LIVE_INBOX, score=99.0)
await _fire()
assert fake.actions.moves == ["junk"]
assert recorded and recorded[0]["action"] == "moved"
assert fake.published and fake.published[0][0] == "plugin.antispam.classified"
async def test_unreachable_engine_delivers_normally(wired) -> None: # type: ignore[no-untyped-def]
"""Acceptance 2: no engine, no interference."""
install, recorded = wired
fake = install(LIVE_INBOX, score=None)
await _fire()
assert fake.actions.moves == []
assert recorded and recorded[0]["action"] == "none"