c.Email

c.Email adds encryption and verified sending to an existing Gmail or Outlook address. It is best suited to people who want stronger protection without changing their email address, and the free tier covers its main security features. Setup takes an identity check, and the most restrictive message mode adds ongoing verification.

Overview

Rather than asking users to create a new mailbox, c.Email connects to Gmail or Outlook and lets them continue using their current address. Senders can choose among Not secure, Secure, and For Your Eyes Only levels, matching the protection to the message. Verified sending uses identity verification and cryptographic proofs to authenticate the sender.

Getting started requires a one-time check using an existing ID and a liveness check. Identity data stays on the user's device. That is a meaningful privacy safeguard, but the identity step is extra setup friction for anyone seeking a quick email add-on.

Key features

Device-based encryption

Messages are encrypted on the sender's device and decrypted on the recipient's device, rather than being stored, encrypted, or decrypted on c.Email servers. The system combines classical cryptography with ML-KEM, the post-quantum standard published by NIST. Business use has a server-side exception, so this handling should not be assumed for every business configuration.

For Your Eyes Only

This strongest mode requires continuous liveness verification from the intended recipient. That offers an additional check around access to sensitive messages, but it also makes this mode less convenient than ordinary protected email.

Existing addresses and multiple accounts

Gmail and Outlook support means users can keep familiar addresses, and the free plan permits unlimited email addresses. That breadth is useful for people managing multiple accounts without wanting a new c.Email address. c.Email is also built on cDot, a protocol for encrypted identity, email, messaging, and payments; its C-layer stores public encryption and verification keys on a distributed blockchain of independent nodes. The C-layer is under development, and anyone can run a node.

Pricing

Free — free. The free plan includes end-to-end encryption, verified sending, post-quantum security, For Your Eyes Only emails, and unlimited email addresses, with support for existing email addresses. It is the natural starting point for individuals who want the core protections without a subscription. Premium capabilities are planned as the product suite expands.

Premium — custom pricing. Advanced features for individuals are coming soon. This may suit individual users who later need more than the free tier, but it is not a current option.

Business Self-Serve — custom pricing. This upcoming plan is aimed at teams and organisations, with server-hosted encryption using either the customer's server or a server included in the plan. It also includes efficient compliance with data protection regulations.

Business Plus — custom pricing. Coming soon, this plan is for customised business protection and enterprise-level secrecy. There is no current paid tier to compare with the free offer; the listed business options are future plans, not a present upgrade path.

Platforms

c.Email is available as an app and browser extension, including a Chrome extension. The platform information also identifies mobile apps, while Gmail and Outlook are the supported email integrations.

Who it's for

c.Email makes the most sense for people who want encrypted messages and sender verification while retaining a Gmail or Outlook address, particularly those who value device-side handling and post-quantum cryptography. It is less suitable for someone unwilling to complete an identity check, or for a recipient who would find continuous liveness checks burdensome. Organisations can consider the planned business plans, but those options are not yet available.

Pros and cons

• Pros: The free plan includes encryption, verified sending, post-quantum security, For Your Eyes Only, and unlimited addresses, so its core protections do not require a paid plan.
• Pros: Existing Gmail and Outlook addresses can be connected, avoiding a forced address change.
• Pros: Identity data remains on-device, and ordinary message encryption and decryption happen on the sender's and recipient's devices.
• Cons: Setup requires an ID and liveness check, adding a hurdle before use.
• Cons: For Your Eyes Only requires continuous liveness verification, which trades convenience for added access control.
• Cons: Premium and business plans are coming soon, leaving no current paid option for users or teams that need features beyond the free tier.

Alternatives

FlowCrypt is worth considering for users who want an extension-based freemium option with a stated free-plan cap of fewer than 100 users and a 5 MB attachment threshold.

SecureMyEmail may suit people who prefer a freemium service with Windows, macOS, iOS, and Android platform support; its free plan allows one email address.

Mailvelope is another freemium extension and web option, with a free trial and a stated Mailvelope Business price of €3 a month for 1–49 users.

DataMotion Secure Email Exchange is a freemium alternative with Android, iOS, API, and web platforms and an enterprise offering priced through sales.

Virtru Email Encryption may fit teams seeking a paid product with web, desktop, and mobile platforms; its Starter plan is $119 a month billed annually for 5 users.

Lockbin is a freemium option with web, desktop, and Linux platforms; its free plan is for one user and includes a 25 MB attachment limit and six months of inbox storage.

RMail is a paid alternative with web and desktop platforms.

Send It Secure is a freemium alternative with a guest plan that includes 30-day retention, 25 MB files, and 10 lifetime sends to non-paid users.

Browse more options in Email Encryption Software or File encryption tools.

Verdict

Choose c.Email if you want end-to-end encryption, verified sending, and post-quantum security without abandoning Gmail or Outlook, and can accept identity verification during setup. Its free plan is unusually complete for those core needs. Look elsewhere if that onboarding or continuous liveness verification is too much friction, or if you need a paid individual or business plan now.