Professional using her smartphone for secure messaging

9 min

Updated 28 07 25

Secure Messaging Showdown: Comparing Tools for Private Digital Comms

One guessed password brought down a business that had survived for over 150 years. When the stakes are that high, secure messaging has to be built in from the start.

Whether you're texting a friend or emailing a client, sensitive information shouldn't be left exposed. It needs the right protection in place.

Standard email and everyday chat apps can leave messages exposed - with up to 50% of UK businesses reporting cyber attacks.

Secure messaging tools help protect what you send by scrambling it with encryption. Some also confirm the identity of who receives it.

But not all secure tools are built the same. Certain platforms are great for a quick chat. Others are better for formal documents. Some keep no record of messages. Others offer full visibility and control.

Let’s compare the most widely used secure messaging and email tools - how they work, what they protect, and which might suit you best.

Secure Messaging Apps

Secure messaging apps are now common for private and workplace chats.

They focus on real-time conversations protected by end-to-end encryption (known as E2EE), which makes sure only the sender and recipient can read the messages.

One of the problems of these tools is that they often require both parties to use the same app and don’t always offer controls for identity verification, audit logging, or business integration - making them less suitable for regulated environments.

Let's take a look at each of them in detail.

Signal

Signal is a free, open-source app widely recognised for its strong privacy protections. It uses the Signal Protocol - a highly regarded standard for end-to-end encryption.

Messages are encrypted locally, and Signal stores almost no metadata about who you message or when.

Pros: Strong encryption, minimal data collection, open-source code.

Cons: Requires a phone number to register (rather than an email address), lacks business tools and integrations (such as for auditing), and provides no recipient identity authentication or challenges.

Best for: Personal conversations where privacy is a priority.

WhatsApp uses the same encryption as Signal for chats, calls, and files. It’s widely used and offers a Business Platform for enterprise messaging.

However, it collects detailed metadata (such as contacts, device info, and usage stats), now used to display ads to free users.

The source code is also not fully open, so it's hard for independent experts to verify the security.

Though they do provide a business option, on the Business API, messages are decrypted so they can be processed by a company or chatbot - meaning they are not end-to-end encrypted.

Pros: Encrypted by default, familiar interface, business messaging tools.

Cons: Collects metadata, no full E2EE for business use, closed-source.

Best for: Day-to-day messaging and basic business chat with customer support.

Telegram only uses end-to-end encryption for its “Secret Chats” - which must be manually enabled per conversation.

Regular chats are encrypted between your device and Telegram’s servers, meaning the company could technically access your messages.

This setup enables convenient features like multi-device sync and cloud backups but sacrifices full confidentiality.

Its encryption protocol, MTProto, is proprietary and less widely-reviewed than standards like the Signal Protocol.

Pros: Cloud sync, large group support, open-source client apps.

Cons: Not E2EE by default, closed server code, no recipient authentication.

Best for: Large group chats and broadcast channels where convenience matters more than confidentiality.

Most secure messaging apps require both sender and recipient to use the same tool - a key limitation for professional use.

Secure Email Platforms

Secure email tools let you send protected messages and documents to any email address - without requiring the recipient to install an app or create an account.

They typically include encryption, identity verification, message tracking, and compliance controls - making them well suited for document-based communication and regulated business use.

Mailock

Mailock provides end-to-end encryption and verifies recipients using challenge questions, SMS codes, or trusted IDs like Unipass.

It includes proactive security alerts that prompt users to encrypt emails when sensitive information is detected, helping to prevent data loss.

The platform integrates with Outlook or works via a secure web app.

It offers tracking to show when a message is opened or replied to and is designed to be simple for recipients to access without installing software.

Pros: Identity verification, message tracking, regulatory compliance (GDPR, NHS DSPT, ISO 27001), and recipient simplicity. Can be integrated with any identity verification method for the enterprise.

Cons: No Gmail plugin (but browser access or server integration is available).

Best for: Sending sensitive documents by email in regulated industries - ideal for business use, especially customer communications.

"Far too often, enhanced data security and effortless user experiences are seen as competing objectives.

This is a misconception. Security and usability can - and should - go hand in hand."

Paul Holland, Founder, Beyond Encryption

Proton Mail

Proton Mail offers end-to-end encryption between Proton users and stores all data in a zero-access format (meaning Proton cannot read your messages or see your contacts).

When emailing non-users, you can add a password so they can access the message securely in a browser.

However, it offers limited recipient authentication options (beyond a password - e.g., no SMS verification) and enterprise flexibility.

Pros: Zero-access encrypted storage, based in Switzerland (strong privacy laws), open-source.

Cons: Requires a separate Proton email address and inbox, limited identity verification, less suited to business workflows.

Best for: Personal use and privacy-focused communication.

Tutanota

Tutanota encrypts everything from subject lines to calendars and contacts, using strong post-quantum algorithms.

It’s fully open source and claims not to track user data.

External recipients can access secure messages through a shared password or SMS code just as with Proton Mail.

Pros: Full encryption coverage, no user tracking, open-source.

Cons: Requires an account, technical setup may not suit non-specialist users, fewer features for business users, no recipient authentication.

Best for: Technical users seeking a private, standalone encrypted mailbox.

Microsoft Outlook Encryption

Microsoft 365’s Purview Message Encryption offers email protection with built-in access controls.

External users can open secure messages using a passcode or by signing in with an account.

There are some logging, storage, and encryption options suited to the enterprise. However, management is technical, resource-intensive, and it offers limited identity authentication.

Pros: Seamless for Outlook users, integrates with Microsoft ecosystem, enterprise-grade compliance (ISO 27001, HIPAA).

Cons: Not zero-access (Microsoft retains access), clunky for non-Microsoft recipients, limited message tracking and authentication.

Best for: Businesses already using Microsoft 365 and looking for native integration.

Gmail Confidential Mode

Gmail’s Confidential Mode adds basic privacy features such as message expiry and the ability to disable copying or forwarding, but messages are not end-to-end encrypted and remain accessible to Google.

Pros: Built-in for Gmail users, simple interface, restricts message actions.

Cons: Not end-to-end encryption, no identity verification, Google retains access to message content.

Best for: Casual Gmail users who want added control - but not suited for sensitive or regulated data.

Virtru

Virtru adds encryption to Gmail and Outlook. You can choose who can read a message, revoke access, and view audit logs.

It uses client-side encryption, allowing businesses to manage their own encryption keys for flexibility and control.

Pros: Strong access controls, audit trails, works with Gmail and Outlook, enterprise hosting options.

Cons: More complex setup, geared towards enterprise users, can be difficult to access for external recipients (e.g., customers) to access.

Best for: Larger organisations with strict compliance or zero trust architecture requirements, for internal use.

Egress Protect

Egress provides strong encryption, identity verification, and AI-powered data loss prevention.

It alerts users if they’re about to send sensitive data to the wrong person or unsecured.

Egress is used widely in UK government and health sectors, however recipients must create an account to access messages. There are also limited options for identity authentication.

Pros: Advanced data loss prevention, compliance with NHS and financial standards.

Cons: Requires account registration, can be complex to navigate for new users, limited identity authentication.

Best for: Public sector institutions managing high-risk communications that prioritise security over ease-of-use for recipients.

Secure email platforms now rival messaging apps in usability - while offering better compliance and traceability.

Which Should You Choose?

Secure messaging apps are great for fast, informal conversations.

They’re intuitive, widely used, and offer strong privacy - but usually require both parties to use the same platform and don’t offer much control or compliance support.

Secure email, on the other hand, works with any recipient. It adds verification, message tracking, and supports professional workflows like document delivery, approvals, and sensitive customer communications.

Messaging apps: Ideal for team chat and casual contact - but limited when cross-platform, accountability, or privacy assurance is required.

Secure email: More suitable for formal communication - especially when you need to send confidential documents or prove who opened what, when.

For individuals, tools like Signal or Proton Mail provide simple, secure ways to protect personal conversations.

For businesses and professionals dealing with sensitive data, Mailock or Microsoft Message Encryption (MPME) provide strong encryption, controls, and compliance features, though MPME is not designed to provide a smooth customer experience.

Ultimately, the best tool is the one your audience can confidently use - without compromising on protection.

"Secure email allows businesses and their clients to exchange sensitive information with confidence while taking advantage of all the benefits of email."

Paul Holland, Founder, Beyond Encryption