Inbox, reimagined.
A calmer, faster, more modern way to work with email. Skybox unifies every mailbox, calendar, contact and account into one workspace — even when your inbox isn't.
Re: Q3 planning deck
20.05.2026, 09:12| From: | Marco Reus <marco@acme.co> |
| To: | you@acme.co |
Hi —
Thanks for pulling the Q3 deck together — it's in good shape. A few notes before this goes upstairs:
- Slide 4 — let's collapse the two revenue charts into one. The second one just repeats the story.
- The roadmap on slide 9 is strong. Add the Skybox mobile milestone so it doesn't look like we slipped it.
- Small typo on slide 12 — "recieve".
I can hop on a call tomorrow morning if that's faster — otherwise I'll send tracked edits back by Thursday EOD.
Best,
Marco
One client for every inbox you already own — nothing to migrate, nothing to forward.
Accounts grouped into profiles, not stacked into a pile.
Work, Personal, Side project — each profile is its own workspace with its own accounts, sidebar and unified inbox. Most clients stack mailboxes on top of each other; Skybox keeps the contexts apart and the messages together.
Switch contexts, not apps.
One keystroke swaps the whole workspace — sidebar, accounts and settings — without signing anything in or out.
Every inbox in one stream.
Search across accounts, triage in batches, move messages without thinking about which server they came from.
Calendar and contacts,
right beside the mail.
Skybox syncs calendars and address books over CalDAV and CardDAV — Google, Microsoft, Fastmail, or any server you point it at. Month, week and day views, recurring events, and contacts that autocomplete in the composer across every account in the profile.
When an invitation lands in your inbox, answer it there: Accept, Maybe or Decline sends the RSVP and files the event into the calendar you pick — cancellations, updates and proposed new times included.
Calendar and contacts are our newest additions — in daily use and improving fast.
Built for the way email actually works.
One identity across every device, keyboard-first triage that keeps up with you, and the same workspace in the browser, on the desktop and in your pocket.
One identity, every device.
Accounts, profiles, layouts and settings sync wherever you sign in. Open Skybox in a new window and find the workspace exactly the way you left it.
Keyboard at the speed of thought.
Every action has a shortcut, and a command bar catches everything else. Triage a hundred messages without lifting your hands off the home row.
Browser, desktop, phone.
The same account in a tab, in its own window on your Mac or PC, and on iPhone and Android — with push notifications when mail arrives, and an unread count on the app icon that follows what you've already read somewhere else.
An MCP server, in every inbox.
Skybox exposes your connected accounts through MCP. Claude — or any agent you trust — can search, read, draft and act across all of them, with scopes you set.
- UnifiedOne search across every profile and account.
- ScopedPer-tool auth — agents see what you allow.
- EncryptedCredentials encrypted at rest — your mail is never stored.
Sent Michael the receipt.
Done — Michael has the receipt.
Exactly what happens to your data.
No sweeping promises — the actual design, including the tradeoff we chose, so you can decide for yourself.
What Skybox stores.
Your account credentials and OAuth tokens, encrypted at rest on our servers. That's what lets one login carry every account to any device — Skybox decrypts them server-side only to open a connection to your providers.
Your mail itself is never stored. No message, calendar or contact data sits in a database or persistent cache — the only thing kept warm is the live connection to your mail server, so repeated queries stay fast.
What encryption at rest protects — and what it doesn't.
It protects against a stolen database, a leaked backup, storage-level snooping. It does not protect against a compromise of the running server, an insider with key access, or a legal request — the relay has to be able to decrypt credentials to use them. Skybox is not a zero-knowledge system, and we won't pretend otherwise.
Why not zero-knowledge?
Because zero-knowledge and “one login, everything on every device” are mutually exclusive. If nothing server-side can open a connection while you're logged out, there is no push, no search across accounts — and a forgotten password becomes total, unrecoverable account loss.
In a web app the guarantee is weak anyway: the server ships the decryption code on every load, so a compromised server defeats it regardless. For a web-first, multi-device client, server-held keys are the coherent design. We chose this tradeoff deliberately.
In the path, by design.
Skybox is a relay: your mail passes through it on the way to your browser, protected by TLS on every hop but readable by the relay in motion. That's inherent to the architecture, not a flaw. If your threat model requires local-only handling, a local client is the better tool — we'd rather tell you that than have you discover it.
What else leaves the app, and where it goes.
Product analytics, crash reports and session replays go to PostHog on European servers — counts and route patterns, never a subject, an address or a message. A replay is masked before it leaves your device: every text is dots unless we marked it as our own chrome, and the message body isn't recorded at all, it's cut out. Masking is code, not a promise, so we say that plainly — and nothing is stored on your device for any of it. This marketing site runs none of it.
And mobile push: a notification about new mail carries the sender and the subject line through Google's push service, on iPhone onward to Apple's. That's how push works on both platforms — the alternative is no notifications, which you can choose. The browser and desktop apps use neither; they get their events straight from us.
Skybox is live.
In active development — and usable today. Open it in your browser and connect your first account in minutes.