Show HN: InBox Wall – A local-first, open-source email sanitizer for AI agents

InBox Wall is a local-first Python application that sanitizes incoming email HTML before an AI assistant processes it, removing hidden text, invisible Unicode characters and known prompt-injection patterns. It fetches mail via IMAP in read-only mode, stores clean text in a local SQLite database while quarantining blocked threats separately, and serves the clean text through a local REST API and MCP server. The project documents its defenses, known limits (attachments, URLs, images and social engineering are not covered) and recent security fixes.