Poller repeatedly reprocesses failed/rejected emails

[rdyson]

Problem

The poller only skips messages labeled processed, but it also writes failed and rejected labels. Those messages are therefore picked up again on future polls.

Repro

1. Send an email from a sender not in allowed_senders.
2. Poll once; message gets labeled rejected.
3. Poll again; same message is re-evaluated.

Similar behavior occurs for messages labeled failed.

Expected

Messages labeled processed, failed, or rejected should be skipped by default.

Actual

Only processed is skipped.

Impact

• Repeated API calls on messages already classified.
• Extra logs/noise.
• Potential repeated scrape attempts on permanently bad content.

References

• poll_inbox.py:132
• poll_inbox.py:146
• poll_inbox.py:184