Email IMAP Full Fetch

Core Goal

• Fetch one target email by stable message reference from IMAP.
• Enforce lookup order: HEADER Message-Id exact match first, then uid fallback.
• Download full raw MIME via BODY.PEEK[].
• Parse and return headers, full text body, html body, and attachment metadata.
• Save .eml and attachment files to disk with filename safety and idempotent indexing.

Standard Flow

1. Input must include message_id_norm from stage-1 routing output (mail_ref.message_id_norm).
2. Use fetch --message-id "<message_id_norm or raw Message-Id>" as the default path.
3. Use fetch --uid "<uid>" only when no usable message-id is available.
4. Keep mailbox selection consistent with stage-1 (--mailbox or IMAP_MAILBOX).
5. Read JSON output and continue downstream processing with returned mail_ref.

Commands

Fetch by Message-Id (preferred):