Mail-Archiver is a production-grade ASP.NET Core 10 web application for archiving emails from IMAP, Microsoft 365 (Graph), and local imports (MBOX, EML). It provides a full MVC UI for searching, viewing, exporting, restoring, and managing archived emails, alongside a read-only REST API (v1) and a Model Context Protocol (MCP) server for AI agent integration. The system features background job processing for sync, batch operations, deduplication, retention policies, and audit exports, all backed by PostgreSQL with full-text search. Authentication supports local password (PBKDF2), OpenID Connect, and API keys, with two-factor authentication and role-based access control. The codebase is well-structured with clear separation of concerns: provider-specific services (IMAP, Graph, Mbox), shared utilities, and a core service layer. Extensive unit and integration tests (xUnit) cover critical paths, and Docker Compose provides a reproducible test environment. While some technical debt exists (raw SQL in core services, in-memory job tracking, German comments in places), the overall architecture is solid and the reusable components (static helpers, deduplication strategies, background job patterns) demonstrate high craftsmanship.