CloudBox, right where you work

Send encrypted large attachments straight from your email — one click, no more attachment limits. Free, account-less, zero-knowledge.

Gmail

A browser extension that adds a Send with CloudBox button to Gmail's compose window. Attach any size — it uploads encrypted and drops a download link into your email.

  1. Download the extension and unzip it.
  2. chrome://extensions → enable Developer mode → Load unpacked.
  3. Open Gmail compose → click Send with CloudBox.
AvailableDownload extension

Outlook

An add-in for Outlook on the web, Windows and Mac. Adds a CloudBox button to compose so you can send big files encrypted, without hitting attachment limits.

  1. Download the manifest.
  2. Outlook → Get Add-ins → My add-ins → Add a custom add-in → From file.
  3. Compose → open CloudBox from the ribbon.
Available (sideload)Download manifest

Thunderbird

A Thunderbird add-on to send encrypted large files from compose.

Coming soon

Desktop app

Drag-and-drop send plus a system "Share to CloudBox", for Windows and Mac.

Coming soon

Emaily

CloudBox already powers large-file sending inside the Emaily AI email app.

AvailableOpen Emaily →

Developer API

Add CloudBox encrypted transfer or storage to your own product via a simple API.

AvailableGet access →
Just want to send once? Use the web →