Zivver vs Mailock: Secure Email Solutions Compared

With cyber threats on the rise, organisations are increasingly turning to secure communication solutions to safeguard their data. We compare two popular secure email software solutions: Zivver and Mailock.

In this review, we compare the secure email offered by Zivver and Mailock by examining their core features and benefits, including:

• Outbound email security: Important features to look for in secure email services include encryption strength, authentication methods, and email recall.
• User experience and integrations: When introducing a new solution within your organisation and to your customers, you’ll want the process to stay as frictionless as possible.
• Customer support and price: Ongoing support for the solutions you implement can be an important factor for businesses.

At a Glance

Zivver

• Encryption: RSA 2048
• Verification: Choice of SMS, access code, or email authentication.
• Secure file transfer: Send up to 5TB from O365 and Gmail; recipients receive and download files as normal.
• Email recall: Fully revoke an email from a recipient’s inbox.
• Auditing: Data logging provides an in-depth view of email performance, including emails sent, opened, forwarded, and more.
• Contextual correction: Pre-configured rules, powered by machine learning, spot potential errors such as incorrect recipients or attachments.
• Integrations: Offers an add-in for Microsoft Outlook and a Chrome plugin for Gmail.
• Customer support: Online support and a pre-recorded demo video; Netherlands-based support.
• Pricing: Zivver lists Start, Professional, and Ultimate plans, billed annually, with three-year contract discounts available. Check Zivver for current prices.

Mailock

• Encryption: AES-256.
• Verification: Choice of SMS, Q&A, email authentication, and Unipass authentication.
• Secure file transfer: Send up to 10 attached files, subject to normal email size limits; recipients receive and download files as normal.
• Email recall: Fully revoke an email from a recipient’s inbox.
• Auditing: A comprehensive audit trail enables users to track sent emails, opened or unopened messages, previously set identity verification processes, and email revocations.
• Contextual correction: A pre-configured set of security alerts prompts the user to send securely if present in the email subject or body.
• Integrations: Offers an add-in for Microsoft Outlook and integration with Unipass ID.
• Customer support: One-to-one live demo and a 2-week free trial available. UK-based support.
• Pricing: Free account and paid plans available. Check the current pricing page for plan details.

What Is Zivver?

Zivver is a secure communication platform designed to protect sensitive data shared by email.

Its primary focus is on providing security tools to help stop data leaks caused by outbound emails.

Key features include email encryption, large file transfer, two-factor authentication, email retraction, and an activity dashboard with custom reports and analytics.

Administrators can use audit and communication logs to track user activity, gain insights, and report data incidents to authorities.

Zivver is based in Amsterdam and primarily focuses on helping enterprises in the healthcare, legal, and government sectors.

What Is Mailock?

Mailock, developed by Beyond Encryption, is a secure communication solution aimed at safeguarding outbound email communications.

Its core features - end-to-end encryption, recipient authentication, email revoke, and bulk delivery - make Mailock a strong contender for businesses of all sizes to protect emails and follow industry regulations.

Mailock places a strong focus on usability, making sure users with varying levels of digital knowledge can integrate the software easily with existing email systems.

Based in the UK, Mailock has strong industry ties with the financial and legal sectors, while also catering to a range of other industries.

Zivver Secure Email

1. Zivver Outbound Email Security

Zivver offers a range of tools within its solution to protect confidential emails.

Encryption

Email messages and attachments should be encrypted to prevent interception and other cyber threats.

Zivver uses RSA 2048 to encrypt messages and attachments.

For every new user who creates a Zivver account, a new public or private key pair is generated.

The user’s public key is stored in the Zivver platform for later use when encrypting files and messages.

Learn more about different types of encryption.

Verification

Recipients of Zivver messages must complete a two-factor authentication (2FA) process before they can access the content.

Zivver offers different types of recipient authentication, including:

Verification by Access Code

The sender creates and shares with the recipient a unique code that can be used to open Zivver messages.

This code can be created at an individual or organisational level.

Zivver recommends sharing this code via phone call or in-person correspondence and not emailing it, as emailing could allow malicious actors to retrieve secure messages.

Verification by SMS

If the sender knows the recipient’s phone number, they can have an SMS code sent to the device.

The recipient must enter this code to open their message.

Unlike the access code, SMS codes are generated by Zivver.

Verification by Email

Zivver sends an automatically generated access code by email. This is considered the least secure method, as anyone with inbox access can open the secure message.

Verification by Zivver Account

When sending to another Zivver account holder, the recipient automatically gains access without additional verification.

Secure File Transfer

Zivver offers a secure file transfer service, allowing large files containing sensitive data to be sent securely using an existing email client.

Zivver supports file sizes of up to 5TB, which can be attached to secure messages sent through Gmail, M365, or Outlook.

This may appeal to users currently limited by smaller file size restrictions in standard email clients.

Email Recall

Zivver messages and attachments can be revoked after they have been sent.

Revoking a message removes it from all recipients’ inboxes, including those in CC and BCC.

To use this feature, the Zivver Office Plugin must be installed and used by the sender, with secure mailing switched on.

An expiration period can also be applied to Zivver messages, after which the recipient or both the recipient and sender lose access to the emails once the set time has passed.

This feature supports organisational data retention policies.

Learn about the challenges of recalling emails in Outlook.

Contextual Correction - Business Rules

Zivver uses machine learning to help users spot potential errors, such as sending to an incorrect recipient or attaching the wrong document.

The system also scans emails for keywords that may indicate sensitive or confidential content, prompting users to send messages securely.

This feature is only available to those on a Professional licence or higher.

Because this feature depends on licence tier and configuration, buyers should check how Zivver's current business rules and machine-learning options fit their workflow.

2. Zivver User Experience and Integrations

Zivver provides a simple interface, letting users send and receive secure messages with ease.

It supports integrations with third-party platforms, enabling incorporation into existing email clients such as Gmail and Microsoft Outlook.

Zivver users with a Professional licence can embed the software into their workflows by downloading the dedicated Office plugin or Chrome extension, or by logging into their online portal.

Users can appoint administrators within Zivver, who can set up company-level branding and custom text on notification messages.

Those on an Ultimate licence can switch on proof-of-delivery reports, letting senders know whether outbound messages have been opened.

Based on Capterra reviews, Zivver has an average score of 3.7/5, based on 33 reviews checked on 3 June 2026.

Many reviews highlight Zivver’s ease of use and smooth onboarding. Buyers with complex workflows should still test configuration options before committing.

Some Zivver customers have reported issues integrating with existing databases, such as patient phone number repositories, which can add friction when authenticating recipients via SMS.

Recipients of Zivver messages don’t need to create an account to read or reply, but if they want to compose their own secure messages rather than just replying, they’ll need to set up an account.

3. Zivver Customer Support and Pricing

Zivver provides comprehensive customer support, including training guides, documentation, tutorials, and technical assistance.

Zivver offers three licence types, billed annually or on a 3-year term.

Contracts for multiple licences over three years provide a 20% discount. The licence types are:

Licence Type: Start

For occasional users. Check Zivver's pricing page for the current monthly equivalent.

Includes encryption, email revoke, recipient authentication, and large file transfer features.

Licence Type: Professional

For regular users. Check Zivver's pricing page for the current monthly equivalent.

Includes everything in Start, plus Outlook and Gmail integrations, machine learning, shared mailboxes, and custom notifications.

Licence Type: Ultimate

For enterprise users. Check Zivver's pricing page for the current monthly equivalent.

Includes everything in Start and Professional, plus default message expiration, single sign-on, domain claiming, and proof-of-delivery features.

Mailock Secure Email

1. Mailock Outbound Email Security

Mailock is a secure email solution used by companies of all sizes to protect confidential communications.

It provides a range of security tools:

Encryption

Mailock uses end-to-end AES-256 email encryption to secure messages and attachments, with the ability to attach up to 10 documents per secure message.

AES-256 encryption uses a 256-bit key and meets NSA standards for classified information, making sure that only the intended recipient can decrypt messages.

Mailock messages are encrypted in transit and at rest.

Verification

Mailock users can set authentication challenges to verify recipients and make sure only authorised individuals can access sensitive messages.

Mailock’s authentication options include:

SMS Challenge

Automatically generates a numeric code sent to the recipient’s mobile device.

The recipient must enter this code to access the message.

Q&A  (Question & Answer) Challenge

Q&A authentication asks the recipient a question that only they would know the answer to.

Correctly answering unlocks the message.

Unipass ID Authentication

For financial professionals and organisations using Unipass, Mailock supports identity verification via Unipass ID.

These identity challenges add a critical layer of protection against misdirected emails and unauthorised inbox access.

Learn more about email authentication.

Auditing and Email Recall

Auditing is essential for compliance in regulated industries.

Mailock provides a full audit trail, allowing users to review identity verification processes, track who has opened or failed to open emails, and monitor email revoke actions.

Mailock users can quickly and immediately revoke any messages sent securely, reducing the risk of data breaches from accidental sends.

Senders can also receive read notifications directly in their mailbox when recipients open messages.

Contextual Correction - Security Alerts

The Mailock system includes a set of predefined keywords that, if found in an outgoing message or subject line, will prompt the user to activate encryption and send the email securely.

Administrators can customise these security alerts to match the organisation’s information security policies.

2. Mailock User Experience and Integrations

Mailock is consistently praised for its ease of use and straightforward implementation.

The system supports a wide range of technical abilities, making sure even less tech-savvy individuals can work with it comfortably.

"I gave it to one of our less technical members of staff.

They worked with it well, gave it good feedback, and found it easy to use. That was a big winner for me.”

Tony Cartwright, Operations Supervisor

Mailock prioritises the recipient experience, allowing end users to read and download attachments from secure emails without needing to register for a free account.

For those who want to reply and send their own secure messages, Mailock provides a free account with secure replies and a limited number of sends.

When it comes to integrations, Mailock integrates with Microsoft 365 via a dedicated secure email Outlook add-in.

For financial services, Mailock also offers verification with Unipass ID.

The Mailock read experience can be personalised by administrators who can set up company branding applied to all outbound Mailock messages.

3. Mailock Customer Support and Pricing

Beyond Encryption provides UK-based support for Mailock customers, with Mailock rated 4.7/5 on Capterra, based on 63 reviews checked on 3 June 2026.

All potential customers can book a one-to-one demo and a 2-week trial to make sure the system meets their needs.

“Sometimes when you get new systems and you’re trying to set them up, you think ‘Oh my god I wish I’d never bothered!’

But once we’d had the demo with Carole and she told us how to set it up, it was a simple process.”

Deb Owen, Administration Manager

Mailock offers free and paid plans, with volume-based pricing available for larger deployments:

Licence Type: Free

For occasional sends, a Mailock Free licence includes encryption, Q&A email authentication, Outlook add-in, and read notifications.

Licence Type: Pro

For professionals and teams, a Mailock Pro licence is a paid plan. Check the current pricing page for the latest per-user price.

It includes all Free features plus SMS and Unipass authentication, company branding, security alerts, audit trails, and message recall.

Licence Type: Enterprise

Mailock Enterprise is designed for high-volume protection. Pricing varies depending on the package you choose.

It includes all Pro and Free features plus advanced delivery analytics, API control and monitoring, a choice of on-premise or cloud deployment, and automated or bulk sending.

Find out more about Mailock pricing and plans.

Zivver vs. Mailock

When it comes to secure communication solutions, every business has different requirements to protect internal data and their customers’ personal information.

Both Zivver and Mailock are reliable options.

Let’s summarise the key differences:

Zivver Strengths and Trade-Offs

Offers larger file transfer capabilities and machine learning-based business rules.

However, these corrective measures are new and causing some friction with existing customers.

Does not offer automation for enterprise email delivery.

Mailock Strengths and Trade-Offs

Uses AES-256 encryption, unique Unipass ID integration for financial services, bulk send capabilities, flexible monthly billing, UK-based support, and a dedicated demo and trial period.

FAQs

What Is Secure Email?

Secure email is a way of sending messages and attachments that uses encryption and verification steps to protect against cyber threats.

How Does Encryption Protect My Emails?

Encryption scrambles your email content so only the intended recipient can read it, reducing the risk of unauthorised access.

What Is the Difference Between Zivver and Mailock?

Zivver offers large file transfers and machine learning, while Mailock focuses on recipient experience, Unipass integration, and flexible billing.

Do These Solutions Comply with FCA Guidelines?

Both Zivver and Mailock can help businesses follow FCA rules, especially in the financial and legal sectors where data security is critical.

How Do I Choose the Right Secure Email Solution for My Business?

Consider industry regulations, needed features, customer support requirements, and budget. Testing free trials can help you decide.

References

Zivver pricing, Zivver, checked 3 June 2026

Zivver Reviews, Capterra, checked 3 June 2026

Mailock Reviews, Capterra, checked 3 June 2026

Reviewed by

Sam Kendall, 03.06.26

Sabrina McClune, 19.12.2024

This content is for general information only and is not legal advice.