Skim
A free AI email client for Windows that doesn't suck (that hard).
Minimalist, native, fast. Bring your own AI key for the assistant and co-writer. No subscriptions, free forever.
Free & open source · ~5 MB installer · no admin rights needed
Grab Skim_x.y.z_x64-setup.exe from the latest release
Website · Download · Report a bug · Contribute
Why Skim
Email clients usually come in two flavors: a browser cosplaying as an app, or a monstrous do-everything suite with ICQ-era vibes. Skim is neither:
- ⚡ Native, not Chromium. A Rust core with a system WebView2 UI (Tauri 2) — no bundled browser like Electron. The installer is a few megabytes, cold start is instant, idle memory is modest. No admin rights.
- ✂️ Half the features, cut on purpose. No calendar, no contacts manager, no rules, no filters, no snooze — none of the stuff you never actually use anyway. Fewer buttons, less cognitive load. Need a do-everything suite? Install Outlook.
- 🎯 Actions when you need them. Buttons appear only when they're useful; there's no menu bar at all. Skim's job is to surface the right action at the right moment.
- 🔒 Local and private by default. Your mail syncs over IMAP straight into a local SQLite cache. It works offline, search is instant, and nothing ever passes through anyone else's servers. Zero telemetry, zero anal probes.
- ✦ AI on your terms. Paste your own key — Anthropic (Claude), OpenRouter for models from any vendor (Claude, GPT, Gemini, Grok, …), or any OpenAI-compatible endpoint, including a local model (Ollama, LM Studio, vLLM) that never leaves your machine — and Skim drafts in your voice, summarizes threads, answers questions about a message, and chats across your whole mailbox with cited sources. No key? Skim is a great mail client without it. Requests go directly from your machine to the provider; the key lives in Windows Credential Manager.
- 🌍 11 languages, light & dark themes, keyboard-first.
Features
Mail
- Gmail, Outlook, Yahoo, iCloud, or any IMAP/SMTP server (autoconfig for the big ones)
- Google and Microsoft sign-in via OAuth (loopback + PKCE) or app password
- Multiple accounts side by side, plus a unified All inboxes view; compose from any of them with a per-message From picker
- Conversation threading (References/In-Reply-To with subject fallback)
- Archive, delete, star, read/unread — all optimistic with a durable offline queue: act instantly, Skim syncs when the network returns
- IMAP IDLE push + periodic polling; new-mail notifications with a mark-read quick action
- Lives in the tray: closing the window keeps mail syncing in the background; starts with Windows minimized (both optional)
- Compose, reply, reply-all, forward with proper threading headers
- Attachments: open, save; inline images served from the local cache
- Calendar invites get an RSVP card — Yes / No / Maybe answers the organizer the standard way, and Add to calendar opens the
.ics in whatever calendar you already use (Skim itself has none, on purpose)
- One-click Unsubscribe for mailing lists — RFC 8058 one-click POST, unsubscribe e-mail, or the link in your browser, in that order
Speed
- Instant full-text search (SQLite FTS5) over subject, sender, recipients, and bodies
Ctrl+K command palette: search-as-you-type, jump to folders, every command- Keyboard shortcuts:
j/k move · e archive · # delete · s star · u unread · r reply · Ctrl+N compose · / search — press ? for the full list
AI (bring your own key)
There's no "Skim Pro" subscription and there never will be. Paste your own key and the ✦ violet buttons come alive:
- Drafts in your voice — tell it what to say and get a finished, first-person email. Skim can sift through your last 100 sent messages, pick the most representative ones, and match how you write — greetings, sentence length, punctuation. It replies in the sender's language, even one you don't speak
- Refine in dialogue — “shorter”, “add a deadline”, “drop the exclamation marks”. Each tweak lands on the current draft, keeping everything you didn't ask to change; your hand-edits are respected too
- Ask about an email — question one message or the whole thread (up to 25 emails in context), with follow-ups. Answers come only from the content — if it's not in the conversation, it says so
- Mailbox chat — ask “which invoices are still unpaid this month?” in the palette; Skim retrieves the relevant mail (FTS5/bm25) and answers with the source emails cited as clickable chips
- AI Recap — one click digests up to 20 unread emails, what-needs-a-reply first with deadlines and cited sources, and marks them read
- Context-aware — every prompt carries the current date, weekday, time, your timezone, your UI language, and the relevant thread. “Reply that I'll make it by Friday” becomes a concrete date
- Your writer profile — set your name, pick a style (formal / friendly / concise / witty / enthusiastic) or “write exactly like me”, and give standing instructions (“sign as Nick”, “my company is called…”)
- Three ways to bring a key — Anthropic directly (Claude Sonnet 5 default, Opus 4.8, Haiku 4.5), OpenRouter with one key for every vendor (Claude, GPT, Gemini, Grok, or any model slug you type in), or any OpenAI-compatible endpoint — Ollama, LM Studio, vLLM, a gateway, or OpenAI itself — including a local model that never leaves your machine
Your key, your bill: Skim talks to the provider's API directly and adds no markup, no proxy, no accounts. The key is stored in Windows Credential Manager.
This is the beginning of the README. Read the rest at the original. Read the full README ↗
