SYSTEM ONLINE v1.4.2 — 2025.03.04 SHA-256 signed

Your inbox,
unread by us.
A mail client with no server.

Sift is a desktop email client that never sees your mail. No IMAP proxy, no analytics SDK, no "AI" scanning your messages to surface the right coupon. Your credentials live in your OS keychain. Your messages live on your disk. We ship a binary and a public audit — and that is the entire company.

42.6 MB · macOS / Windows / Linux Offline · no account required Source · reproducible build
01 / Threat Model

Three rules we won't break, even if everyone else did.

P.01 / no servers

Your mail never touches our infrastructure.

Sift connects directly from your machine to your provider over IMAP and SMTP. There is no relay, no sync server, no "cloud" folder. If we disappeared tomorrow, your mail would still arrive — because we are not in the path.

proof → 0 outbound calls to *.sift.app in network log
P.02 / no reading

No model reads your messages. Not ours. Not anyone's.

There is no on-device LLM, no smart-reply model, no embedding pipeline. Search is BM25 over a local index. Sorting is rules you write. The only "intelligence" in Sift is yours — we refused the rest as a design constraint, not a config option.

proof → grep -ri "openai\|anthropic\|gemini" src/ returns nothing
P.03 / no lock-in

Your data is yours, in formats you can leave with.

Mail is stored as standard mbox files. Index is a SQLite DB you can open with any tool. Settings are a plain TOML file. If you uninstall Sift on day one, you keep everything — and you can prove it to yourself in under a minute.

proof → ~/.sift/ contains only mbox, sqlite, toml
02 / Specification

Built like a tool, not a product.

Every feature below was chosen because it survives the test: does it work fully offline, with no account, on a machine that has never spoken to us? Anything that failed that test was cut.

F.01

Keyboard-first everything

Every action is bound, every binding is remappable, every list is fuzzy-searchable. The mouse is a fallback, not a requirement.

F.02

Local full-text search

BM25 over a SQLite FTS5 index. Sub-50ms across 100k messages. No query ever leaves your machine.

F.03

Rules, not "AI sorting"

A deterministic rules engine with regex, header matching, and sieve import. Predictable. Debuggable. Yours.

F.04

OS-native secret storage

Credentials live in Keychain, Credential Manager, or libsecret — never in a config file, never in memory longer than required.

keychainmacOS Security.framework
storage~/.sift/mail/ · mbox
index~/.sift/index.sqlite
config~/.sift/sift.toml
F.05

Multi-account, unified inbox

Unlimited accounts. Color-coded. Per-account signatures, identities, and outbound SMTP. Switch with ⌘1⌘9.

work@fastmail● 12 new
personal@proton● 3 new
legacy@gmail○ archived
F.06

PGP & S/MIME built in

Sign, encrypt, verify. Keys managed via gpg or native. Autocrypt supported. No plugin required.

F.07

Plain-text composer

Markdown to HTML on send. No rich-text editor, no tracking pixels, no remote images by default. Your words, your bytes.

F.08

Scheduled send & undo

Hold any outbound message in a local outbox for up to 60 seconds — or schedule it for any future time. Cancel with one key.

F.09

Reproducible builds & public audit

Every release is built from a tagged commit via a deterministic pipeline. The SHA-256 of the binary you install is published alongside the source, signed with our long-term key, and verifiable locally with sift audit --verify-bin. Two independent reviewers audit the diff between minor versions; their reports are public, including the things we refused to fix and why.

commit9f2a4c1 · tag v1.4.2
binarySift-1.4.2.dmg · 42,611,232 bytes
sha256a3f1 8c2d 4e7b 9012 5cf8 6d4e 2a91 0b73 …
signed by0xB87D 4F12 · audit@sift.app
reviewersM. Vernet · K. Ito · reports/sift-1.4.2.pdf
03 / Price

One number. Paid once. No subscription.

SIFT — SINGLE LICENSE

$39 once. That is the entire pricing page.

One payment, every future update included, forever. No tiers, no "Pro" version, no per-seat enterprise dance. If you want a refund for any reason within 60 days, you email one person and they send it. We do not ask why.

$39USD
all platforms, one purchase
all future updates
up to 3 personal machines
no subscription, ever
no telemetry, no upsell
Buy a license
04 / Install

Download Sift. Run it offline. Keep it forever.

The binary below is the same one we ship to paying customers. Try it free for 14 days, no account, no email required. If it ever phones home, the audit failed and you should not have paid us.

verify → sha256: a3f18c2d4e7b90125cf86d4e2a910b73a3f18c2d4e7b90125cf86d4e2a910b73
signature → -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEE… -----END PGP SIGNATURE-----
audit → reports/sift-1.4.2.pdf · signed by M. Vernet, K. Ito · 2025.03.04