Multiple accounts
Add as many as you like. Star something, archive it or bin it here, and it changes everywhere else too.
New
Cursus Bridge is here
Email that doesn't
Email that doesn't
spy on you.
A small, fast, open source email app for Windows and Linux. All your accounts in one place, and you can run the whole thing from the keyboard.
Everything you need.
Nothing you don't.
A complete mail client. Accounts, conversations, search, attachments, drafts, undo send. It stops there, and that is the point.
Conversations, not fragments
Replies gather into one view. Older messages fold away, so a long thread still reads like a conversation.
Send your way
SMTP or Resend, whichever you prefer, per account. Paste images straight in. After you hit send you still have half a minute to change your mind.
Sends that can't get lost
Lost the connection? The message waits in the outbox and leaves as soon as you are back online.
Instant search
Press Ctrl+K anywhere in the app. Results land before you finish typing.
Hands on the keyboard
Walk the inbox with j and k. Reply with r. Archive with e. The mouse is optional.
Truly portable
Drop it in any folder you like. Everything it keeps lives right beside it, so moving the folder moves the whole thing.
Passwords stay safe
They go into the system keychain, never in plain text inside the app.
Press Ctrl+K
Search that actually works.
Type half of what you remember. The right message shows up before you finish.
It looks through subjects, senders and message bodies. Click a result to jump straight there.
- Fast even with thousands of messages.
- One click to index everything you already have.
- Works the same across every account.
Hands stay home
The keyboard is the inbox.
Most things take one key. Move, open, reply, archive, send, search.
They are grouped by what they do, so you stop thinking about them fairly quickly.
j
Next thread
arrow down works too
r
Reply
a for all, f for forward
k
Previous thread
vim style
s
Star
! for importance
e
Archive
selection or focused
⌘K
Search
Ctrl on Windows / Linux
c
Compose
opens fresh draft
Shift
Range select
+ j/k for bulk actions
22 shortcuts in total · full list inside Settings
There's no AI in Cursus.
You bring your own.
An optional second app that sits next to Cursus. Point Claude or a script at it and it works with the accounts you already have. Leave it out and nothing changes.
Speaks agent natively
One line connects your inbox to Claude Code. Nothing to write, nothing to wire up.
$ claude mcp add cursus --scope user -- ./cursus-bridge mcp Added stdio MCP server cursus list_accounts the identities you already configured list_folders the IMAP folder tree of an account list_messages recent messages, with their uids read_message headers, body as text, attachments send_email send as one of them
No server.No port.
It runs, does the job and closes. Nothing stays open on your machine.
Your credentials stay put
It uses the accounts Cursus already has. Nothing to set up a second time.
And plain scripts, too
Every command answers in JSON, so it fits into whatever you already run.
$ cursus-bridge messages --account you@example.com --unread [ { "uid": 4211, "from": "sara@example.com", "subject": "Q3 review" }, { "uid": 4209, "from": "billing@example.com", "subject": "Receipt #4218" } ]
Read it before it leaves
Ask for a dry run and you get the finished message back without any of it being sent.
Nothing happens quietly
Whatever it sends lands in your Sent folder, next to the mail you wrote yourself.
Capped on purpose
One message only reaches so many people at once. Going wider is something you ask for.
Anything you connect to it gets the same access to your mail that you have. How it works
Stop paying to read your own email.
Most mail apps charge every month to read messages your provider already delivers. Here is what they ask for.
-
Superhuman€30/moPremium positioning, status pricing.
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Spark Pro€22/moThe free tier keeps nudging you upward.
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Polymail Premium$24/moBuilt for sales teams. Read receipts and tracking pixels included.
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HEY For You$99/yrPay to use one inbox at a fixed @hey.com address.
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Canary Pro+$100/yrPrivacy as the headline, paywall as the gate.
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Mailbird Premium€55/yrWindows mail that keeps suggesting you pay more.
Cursus
Free. Always.
Open source. No tier above this one, no trial running out, no Pro version waiting.
What's missing
Everything that's not here is on purpose.
A mail app should read mail. Everything else that crept into the others over the years only made them heavier.
No assistant built in
No smart reply, no summaries, no sorting done for you. If you want that, the bridge is there.
No cloud sync
Your data stays on your machine. Move it yourself, or don't.
No telemetry
No usage pings, no analytics, no crash reports. Just your mail servers, and GitHub when it looks for a new version.
No tracking pixels
Remote images stay blocked by default, so senders don't find out when you opened it.
No tier above this one
Apache-2.0, all of it. No trial, no Pro edition, nothing behind a login.
It updates itself
Cursus checks at startup and shows you what changed. It only swaps over when you say so.
About 10 MB on disk
Rust underneath, and it uses the renderer your system already has. No browser shipped alongside your mail.
Portable by design
Everything sits in one folder next to the app. Copy it and you have moved house.
Automation, if you want it
The bridge opens your accounts to scripts and agents, without a second password.
Yours to change
Read it, build it, fork it, send a patch. The repository is the product.
Engineered to last
Tauri 2
Rust
React 19
TypeScript
Tailwind v4
SQLite + FTS5
Apache-2.0
Take your inbox back.
Free and open source. No account, no signup. Point it at your mail and start reading.