professional woman typing on laptop in office
6 min

The Best Secure Email Services To Protect Your Business Data

Posted by Picture of Team B.E. Team B.E.

Digital communications are becoming increasingly commonplace in business – especially when interacting with customers. However, digital channels are at risk from cybercriminals if not adequately protected, and with email being one of the most commonly used communication vectors, ensuring the security and privacy of sensitive data is crucial.

Fortunately, there is a range of secure email services available that offer your business advanced security features. To compile this list, we have thoroughly evaluated the most popular secure email providers on the market based on their encryption methods, authentication processes, and other core considerations, such as pricing and usability.

What Is A Secure Email Service?

A secure email service is a dedicated piece of software that introduces robust security measures into your email communications. This goes beyond the encryption offered as standard by most email providers to include enhanced features that prevent a variety of email-borne threats.

Secure email service often contain strong encryption protocols, as well as some form of identity authentication to protect email contents from threats such as interception and human error. They may also include additional elements such as email recall, security triggers, and comprehensive audit trails to enable compliance with industry regulations.

Why Do You Need A Secure Email Service?

Everyday business is steadily migrating online, with organisations relying heavily on email and other digital services to complete everyday tasks. However, email was only ever created to be a simple file-sharing system, and does not provide the level of protection necessary to prevent against a wide majority of digital threats.

32% of UK businesses are reported to have experienced an attack or breach between 2022 and 2023, with 31% estimating that they were attacked at least once a week. This is largely thanks to a high level of phishing attacks, with 83% of businesses stating that this is one of the most common malicious threats they experience.

However, organisations are also at risk of human-based errors, such as misdirected emails. Research has determined that 88% of all data breaches are caused by an employee's mistake.

Types Of Secure Email Service

Depending on the threats you wish to protect against, there are a variety of secure email services available to utilise. Most secure email software focuses on providing protection from either inbound or outbound threats, so businesses should determine which type of solution they are looking for. To summarise:

  • Outbound email security secures messages and attachments leaving your infrastructure, reducing the chance of a data breach that results from sensitive data being accessed by the wrong person.
  • Inbound email security software deals with incoming emails, scanning them for malicious content and ensuring they remain encrypted until the intended recipient gains access.

Depending on the size of your organisation, there will be different email security options to choose from.

For example, for enterprises and large businesses, a secure email gateway (deployed at server level) can offer comprehensive protection for all your employees who are communicating with your customers. For smaller companies, desktop-based solutions are a cost-effective alternative that can be installed and utilised on an individual basis.

Choosing A Secure Email Service

There are several recommended features you should be looking for when choosing a secure email service. These include:

  • strong encryption, with AES-256 generally considered to be one of the most secure algorithms available today;
  • recipient authentication, which enables senders to verify that the person accessing secure messages is exactly who they say they are;
  • email recall, allowing users to revoke access to secure emails sent in error;
  • audit trails, helping you to adhere to regulations and maintain compliance within your organisation.

Best secure email services

Whether it's Microsoft's Outlook encryption, Egress's machine learning, Zivver's focus on human error, or Mailock's user-centric approach, there is a solution designed to fit your business's specific needs.


Mailock secure email homepage

Mailock is a dedicated outbound email solution, facilitating the secure delivery of confidential information using your existing email setup. Mailock is suitable for a wide range of businesses and is offered as a desktop service or an enterprise-level secure email gateway.

Mailock offers users:

  • end-to-end AES-256 encryption, with recipients granted unlimited secure replies;
  • recipient authentication, with a choice between SMS, Q&A, Unipass, and email verification;
  • full email recall for any message or attachment sent securely, available at user level;
  • Read notifications, informing senders when their secure email has been opened;
  • audit trails, allowing users to track the open status of their messages, attachment opens, and recall statuses;
  • trigger words, composed of a list of pre-determined phrases that, when spotted within the body or subject of an outbound email, prompts the user to send securely.

Key considerations:

Recipients can read Mailock messages without creating an account. If they wish to reply, then can sign up for a free account. This also grants them a limited number of secure sends a month. Mailock also offers an Outlook Add-in that allows users to integrate directly with Microsoft Outlook.

Learn more about Mailock.

Microsoft Purview Message Encryption (MPME)

Microsoft purview message encryption website

Microsoft Purview Message Encryption (MPME), previously known as Office Message Encryption (OME), is Microsoft’s updated secure email service and is included in enterprise 365 packages (such as E5).

Microsoft Purview Message Encryption (MPME) offers users:

  • military-grade AES-256 encryption, with encrypted replies available for recipients;
  • message recall, available only under certain conditions to senders or to administrators who are familiar with PowerShell;
  • recipient inbox access verification, including one-time code, Microsoft sign-in, and Google sign-in;
  • read receipts, which can be requested by the sender upon email composition and either accepted or denied by the recipient when opening a message;
  • a compliance dashboard with a full audit trail, providing details on sent secure messages including timestamps and recall statuses.

Key considerations:
Currently, MPME does not offer any form of recipient authentication or trigger words. Configuration and setup of MPME require the assistance of a Microsoft specialist to activate Azure Information Rights Management and configure it using PowerShell.

For a full breakdown of MPME features, read our full review.

Egress Cloud Email Security Suite

Egress secure email homepage

Egress offers customers secure email as part of their Intelligent Cloud Email Security Suite including Egress Defend, Prevent, and Protect. The combined products are designed to protect against inbound and outbound email threats by reducing human error and risk.

The Egress Intelligent Cloud Security Suite offers users:

  • end-to-end AES-256 encryption, which can be applied by individual users or administrators;
  • configurable access privileges, such as restrictions on forwarding, printing, and downloading;
  • recipient authentication, with users able to set Q&A challenges to recipients which must be passed in order to gain access;
  • machine learning program that analyses outbound email contents for potential threats and prompts users to send securely;
  • integrations with Microsoft 365 and a dedicated Outlook add-in.

Key considerations:

Encrypted replies are available when the recipient has created a free account. Free users have 25 credits per month, with 1 credit equating to 1 recipient.

For a full breakdown of Egress' features, you can read our comparison guide.

Zivver Secure Email

Zivver secure email homepage-1

Zivver is a secure email service designed to protect against outbound email threats, mainly focusing on the risks associated with human error. Their product set delivers machine learning and large file transfer capabilities to prevent the accidental sending of sensitive data to the wrong recipients, thus enhancing overall email security and mitigating potential data breach incidents.

Zivver offers users:

  • RSA 2048 level encryption to secure messages and attachments;
  • recipient authentication, including access code, SMS, and email verification;
  • secure file transfer, facilitating large file sizes up to 5TB;
  • email recall and expiration periods, available when the Zivver Outlook add-in is used;
  • contextual correction, powered by machine-learning capabilities to scan outbound emails for potential errors and recommend secure sending.

Key considerations:

Zivver offers both an Outlook add-in and a Chrome extension. Certain features are only available for particular licence types.

For a full breakdown of Zivver’s features, you can read our Zivver vs Mailock.

The Best Secure Email?

As digital communications continue to dominate business practices, employing the best secure email service is a non-negotiable necessity. With the range of services available, choosing the most fitting solution can seem daunting. However, with Mailock's robust security features, seamless user experience, and flexible packages, it stands out as a leading choice for businesses of all sizes.

Want to learn more about how Mailock can help protect your business data? Try Mailock for a secure, seamless email experience that prioritises the safety of your business communications.


Originally posted on 17 07 23
Last updated on July 28, 2023

Posted by: Team B.E.

Articles and resources posted by Team B.E. are the result of a collaborative production process involving all our experts in digital identity, encryption, authentication and media. To learn more about the individuals in the team, visit our about us page.

Return to listing