A fast, native Windows email client with real Classic-Outlook power-user parity (server-side rules, public folders, COM add-ins, full Exchange calendar) for people being defaulted onto the slow new Outlook
Microsoft is moving Windows users onto 'new Outlook' (a WebView2 web-wrapper) as the default in the 2026 opt-out phase, and power users report it is dramatically slower and missing core features. The unmet need is not 'another pretty email app' (those exist) but a fast, truly native client that replicates the enterprise muscle Classic Outlook users depend on: server-side rule sweeps, public folders, COM add-in compatibility, and full Exchange calendar/contacts.
The email-client graveyard is real, so don't pitch 'a nicer inbox.' The only defensible wedge here is the boring enterprise plumbing every lightweight client skips — add-in compatibility, public folders, and server-side rules over Graph API — and the Oct 2026 EWS shutdown is the forcing function that makes 'we already support Exchange' clients have to re-earn their integration anyway.
landscape (3 existing solutions)
Fast native clients with basic Exchange support already exist (eM Client; Thunderbird's new EWS), and Classic Outlook survives to ~2029, so the mainstream is covered. The genuinely unmet sliver is enterprise power-user parity — COM add-ins, public folders, server-side rule execution, full Exchange calendar — in a client that isn't a slow web wrapper, made more urgent by the Oct 2026 EWS-to-Graph cutover that disrupts even the alternatives.