🐛 Bug: send_email_notification silently drops emails (task reports success) when the Redis origin key is missing

Is there an existing issue for this?

• I have searched the existing issues

Current behavior

send_email_notification in apps/api/plane/bgtasks/email_notification_task.py silently drops all email notifications for an issue whenever its Redis origin key is missing:

base_api = ri.get(str(issue_id)).decode() if ri.get(str(issue_id)) else None
...
if not base_api:
    return

The early return emits no log and raises no exception, so the Celery task reports success while sending nothing.

The key is only written by issue_activity (ri.set(str(issue_id), origin, ex=600)) when an origin kwarg is passed, with a 600s TTL. So the key is absent — and emails are silently dropped — whenever:

• Redis restarts or evicts the key between the activity and the (debounced/delayed) email task,
• more than 10 minutes elapse before the email task reads it, or
• the activity was queued without origin at all (the public REST API paths do this — see #9306, which this bug also masks: the in-app notification bug there is at least visible, but the email half fails with a "successful" task).

Expected behavior

If the cached origin is unavailable, the task should fall back to the configured WEB_URL (settings) for link construction — and at minimum log a WARNING — instead of silently discarding the notification batch while reporting success.

Suggested fix

In send_email_notification, replace the bare return with a fallback to settings.WEB_URL plus a log.warning when the Redis key is missing. (Two small changes; happy to detail.)

Steps to reproduce

1. SMTP configured; user B has email notifications enabled.
2. User A assigns user B to an issue in the web UI (this queues issue_activity with origin, then the debounced email task).
3. Before the email task runs, restart/flush Redis (or wait past the 600s TTL under a delayed worker).
4. Email task runs, returns early, reports SUCCESS; user B receives nothing; no log line indicates a drop.

Environment

Production

Variant

Self-hosted

Version

v1.3.1 (Community); code path unchanged on current default branch as of 2026-06-19

Start in apps/api/plane/bgtasks/email_notification_task.py at send_email_notification and inspect the Redis origin lookup and early return. Check issue_activity for how the 600-second origin key is written. Done means missing origin uses settings.WEB_URL, emits a WARNING, and does not silently report a dropped email batch.