Pelton is a free, open-source email client that searches your whole mailbox locally, online or off. No telemetry, no servers of ours. Your mail stays on your machine.
* Illustrative. Sample messages, not real mail.
Pelton derives selections, links and highlights from a single accent you choose. This is the same picker as the app's settings, wired to the same preview.
A View is a name, an icon and a filter: free text, from/to/subject, a relative date window, and scope like unread-only, flagged or has-attachment. Every View re-runs on startup and after each sync, so the count beside it is live and opening one is instant.
Off by default. Enable them under Settings → Sidebar, as a group in the sidebar or their own tab.
Press Edit menu bar and the live bar turns into its own editor. Drag menus and items into the order you want, hide what you never reach for, and add your own entries, submenus and separators. Built-ins are only ever hidden, never destroyed, so Reset always brings them back.
Star a sender and their mail raises a native notification, whether that is Notification Center, a Windows toast or Linux dbus, even when general new-mail alerts are off. Matching is on the address, so a sender renaming themselves never breaks it.
Pelton now Re: contract review notes
Pelton can register as your system’s mailto: handler, offered once during onboarding and after that as one quiet line in About. Links open a compose with the recipient, subject and body already filled in, and a second click hands the draft to the window you already have open instead of starting a second Pelton.
Pelton speaks the Model Context Protocol, so an AI agent you already use can browse, read and search your cached mail. Read-only, on your machine, off until you turn it on.
Which invoices arrived this month, and what do they add up to?
search_messages "invoice", after: 30d get_message 4 messages Four invoices this month totalling €1,284.40, from Stripe, AWS, Namecheap and Fastmail. The AWS one is the only one still unpaid.
* Illustrative. Not a real exchange.
The last one still ends with you. An agent can compose text for you to paste, but it cannot reach into Pelton and send anything.
list_accountslist_folderslist_messagesget_messagesearch_messagesEnable the server, copy the token, and point your client at it. Pelton shows you this exact snippet with your own token already in it.
{
"mcpServers": {
"pelton": {
"url": "http://127.0.0.1:8765",
"headers": {
"Authorization": "Bearer <your-token>"
}
}
}
} Handing an agent your mail is a real decision. Here is exactly what you are agreeing to.
Nothing listens until you enable it under Settings → External.
Bound to 127.0.0.1. A guard makes binding to a routable address impossible, so nothing else on your network can reach it.
None of the five tools can send, move, flag or delete. The interface they are built on has no method that writes.
Checked in constant time before a request reaches the server, so an unauthorized caller cannot even list the tools. Regenerate it to revoke access.
get_message returns an attachment’s name, type and size. The file contents stay on your disk.
There is no model, no key and no cloud in Pelton. Your agent runs wherever you already run it and reads the mail cached on your machine.
Everything runs locally. These are the parts that already work today.
Search runs against your local store, so even large mailboxes stay quick, online or off.
macOS, Windows, Linux.
No tracking, no crash reports.
Mail lives in local SQLite and on your own provider. Standard IMAP and SMTP, nothing in between.
Pin a message or bulk-download everything since a date for offline reading.
Pelton resyncs off the idle connection the moment the server says something changed, instead of waiting for the next poll.
Notification Center, Windows toasts and Linux dbus, for all new inbox mail or only your starred senders. Both switches start off.
Open PDFs, images and text without leaving Pelton.
Send a message away; it returns unread when you want it.
Schedule a message to send at a time you choose.
Export accounts, preferences and layout into one file.
Eight colors, local by default or synced as IMAP keywords.
Density, themes and layout, tuned to your workflow.
A proper color picker with alpha, editable author and version, and custom CSS. Export the lot as one file.
Browse themes.pelton.app from Settings. Nothing is fetched into the app; downloads come back through the normal import.
When a theme carries both colors and a stylesheet, choose either or both. Remote references are always stripped.
Vim mode in the composer, rebindable shortcuts everywhere, and swipe gestures on the trackpad.
Modal editing in the compose editor.
Rebind keys throughout the client.
Trackpad swipes on messages, configurable.
Learned from mail you send and receive.
Every release ships unsigned builds for macOS, Windows and Linux, the last as a .deb, an .rpm and a plain amd64 binary. First launch needs one extra step on macOS and Windows, since the builds are not code-signed.
Detecting your platform and the newest build.
Pelton is written in Go with Wails, so it stays light on memory without a bundled browser. It is still early, and the source is the best place to see where it stands.
The full source is public. Read it, build it, fork it, ship your own.
Bug fixes, UI polish, backend Go, translations. Open an issue or a pull request.
No accounts, no upsells. Talk to us on Discord or by email.
