Email Ingestion for RAG Format Matrix | Source | Library | Attachments | Threading Info | Auth | |--------|---------|-------------|----------------|------| | EML files | (stdlib), | Yes | Headers | None | | MSG files (Outlook) | | Yes | Headers + MAPI props | None | | Gmail API | | Download via attachmentId | | OAuth | | Outlook / MS365 | | endpoint | | OAuth | | mbox | (stdlib) | Yes | Headers | None | EML — Python stdlib mailparser (Higher Level) MSG — Outlook Files Gmail API Outlook via Microsoft Graph Thread Reconstruction For Gmail / Outlook the provider already exposes / . Prefer those…