What Is Secure Email? Encryption & Authentication Explained

Secure email solutions use encryption and identity checks to protect email contents from interception, manipulation, and errors. This also helps to make sure messages reach the right people.

Secure email services often have features like outbound email risk warnings, message audit trails, and access controls.

These extras add more protection against common threats.

They play an important role in outbound email security.

"When email interception is a constant threat, safeguarding sensitive information shared outside your systems is just as important as stopping cyber criminals from getting in."

Paul Holland, Founder and CEO, Beyond Encryption (Mailock)

Let's look at what secure email is, why it's needed, and how it works.

Contents

• Who Is Secure Email for?
• Why Is Secure Email Important?
• How Does Secure Email Work?
• What Can Secure Email Protect Against?
• What Email Data Needs Protecting?
• What's the Best Secure Email Solution?

Who Is Secure Email for?

Secure email solutions can be used by anyone who needs to send private information and make sure it reaches the right people.

While they are most commonly used by businesses that deal with confidential customer information, individuals and non-profit organisations may also use secure email services to protect their privacy and sensitive data.

Business secure email services let you deliver information to customers, colleagues, and partners without exposing it to email risk.

"Companies have a responsibility to make sure that sensitive data, especially the personal information of their customers, remains confidential and secure."

Adam Byford, COO, Beyond Encryption (Mailock)

Why Is Secure Email Important?

Attackers routinely exploit small gaps in email security, from misaddressed messages to messages left readable in transit.

Email was invented in 1971 and is now one of the most common ways people and businesses communicate.

It was never designed to protect sensitive data.

Over time, providers have added security measures.

However, the core email network still leaves messages open to interception, manipulation, and error.

As email use has grown, so has the amount of sensitive data being sent.

This gives cyber criminals more ways to exploit it.

• Half of UK businesses were victims of data breaches in 2023/4.
• Email is the top channel associated with data incidents.
• Human error is the top cause of email data incidents.

A secure email solution can protect against these risks.

It makes sure that email messages reach the right people, safely.

"With cyber threats escalating from criminals and state actors, secure email is a critical part of any business communication strategy."

Emily Plummer, Marketing Director, Beyond Encryption (Mailock)

How Does Secure Email Work?

Secure email services work much like normal email, with added security.

You still compose and send messages, but the system adds some important protective layers.

Let's look at the most common features you'll find in secure email solutions.

End-to-End Email Encryption

Encryption scrambles an email and its attachments so no one else can read them.

End-to-end encryption locks the content on the sender’s device and only unlocks it when it arrives at the recipient’s mailbox.

This keeps email data safe even if someone intercepts it.

Learn more about email encryption.

Email Authentication

Email authentication is key for proving who you are, and it takes different forms:

• Account authentication adds extra security to an email account, often at login.
• Recipient authentication verifies the identity of recipients before they can unlock encrypted messages.

Many secure email services let you authenticate recipients with SMS codes, ID scans, or question-and-answer prompts.

These checks help you confirm recipients ‘are who they say they are’.

For many businesses, proving that you sent the message to the correct person is vital for regulatory compliance.

Learn more about email authentication.

Email Revoke

Email revoke lets you block access to a message after sending it.

This helps if you email the wrong person by mistake.

Email revoke goes beyond traditional 'recall', which only works under certain conditions.

With revoke, you can block access to any message at any time, even after it’s been opened.

This feature acts as a recovery method for mistakes and offers peace of mind.

If you slip up, there’s still a way to undo it.

Learn more about recalling emails in Outlook.

"Integrating secure email into daily operations can enhance workflows while providing peace of mind."

Mike Wakefield, CTO, Beyond Encryption (Mailock)

Email Audit Trails

Secure email solutions can provide logs and reports for auditing and meeting regulations.

They may record all recipient interactions, including opens, downloads, and revoke actions.

You can track the status of outgoing emails and opt to get notifications when recipients open them.

In areas like financial services, audit trails are critical.

Many transactions require confirmation of delivery.

Learn more about financial services email compliance.

Email Risk Warnings

Secure email solutions often warn users about risks in outgoing messages.

The system scans for sensitive information and makes sure the right security measures are suggested.

Some solutions also prompt you to double-check recipient email addresses before you press 'send'.

These checks can help prevent errors while also teaching users to be careful.

What Can Secure Email Protect Against?

Secure email solutions help defend against the biggest and most worrying email threats.

Phishing Attacks

In phishing, criminals pretend to be a trusted source, like a bank, to trick you into clicking a link or revealing personal details.

Research shows that 81% of organisations worldwide have seen more phishing attempts since 2020.

Email authentication creates a trusted link between senders and recipients.

This helps people confirm that messages are real.

Email Interception

Email interception is when attackers break into a message between sender and receiver.

They can listen in or change the contents without either side knowing.

With end-to-end email encryption, the message is locked up before it leaves your computer.

Attackers can't read it, even if they intercept it.

Learn more about email interception.

Human Error

We've all had that moment where we say, ‘Oops!’ because we clicked 'send' too soon or chose the wrong contact.

Studies show that over 88% of business data breaches come from employee mistakes.

These incidents can be expensive and hurt a company's reputation, especially if they involve customer information.

Email revoke and email risk warnings help stop sensitive data from being sent by mistake.

Recipient authentication also stops unintended readers from opening messages, even if you send them to the wrong address.

What Email Data Needs Protecting?

Under UK law, certain types of data are labelled as 'sensitive'.

Businesses must understand what qualifies as sensitive data so they can guard it properly.

Personal Data

Personal data is information that can identify a person, such as a name, address, or phone number.

Criminals may use it for identity theft or other scams.

Learn more about personally identifiable data.

Financial Data

Financial data includes details about wealth or transactions, like bank accounts and credit cards.

Thieves can steal money or create fake accounts if they get hold of it.

"Protecting financial information supports compliance and the trust our clients place in us every day."

Carole Howard, Head of Networks, Beyond Encryption (Mailock)

Medical Data

Medical data often appears in patient records.

This sensitive information can include names, addresses, and health details.

Legal Data

Legal data includes legal documents, like contracts, which often share details about agreements or court cases.

Intellectual Property Data

Intellectual property relates to proprietary assets, such as patents, trademarks, or copyrights.

Industry Focus: Financial Services

The financial sector handles sensitive data and high-value transactions.

This makes it a prime target for cyber criminals.

We asked our financial services customers which documents they secure by email.

They said:

• 45% regularly protect anti-money-laundering documents.
• 61% regularly protect proposal and policy documents.
• 42% regularly protect investment valuations.
• 50% regularly protect banking details.

It's clear that in financial services, emailing private information is vital for keeping operations running.

What Are the Consequences of Failing to Protect Data?

The UK's Information Commissioner's Office (ICO) can fine businesses up to £17.5 million or 4% of their yearly turnover if they fail to protect data.

Financial losses from a breach can be huge, but the reputational damage may be worse.

Companies that fail to keep clients’ data safe often see their acquisition and retention rates drop.

The impact of this can last for a long time.

What's the Best Secure Email Solution?

If you're seeking the best secure email service, consider these key points:

Encryption Strength

Many providers use TLS (Transport Layer Security) or PGP (Pretty Good Privacy).

Both are forms of encryption, though each has limits.

TLS encrypts data in transit but doesn't protect emails at rest or provide end-to-end encryption.

PGP gives end-to-end encryption with algorithms like AES-256, which is strong enough for sensitive data.

To be safe, use at least AES-256 encryption for sensitive data.

Learn more about different types of email encryption.

Authentication Type

Think about your security needs and how flexible you want your system to be.

Maybe you want recipients to use an SMS code or a secret Q&A.

Maybe you want biometric options, like a fingerprint.

Each choice has trade-offs in ease of use and security.

Integration Options

Check if the secure email solution works well with your current setup.

For example, Mailock connects with Unipass Identity, a single-sign-on tool for advisers in finance.

Ease of Use

No matter how strong the security, if it's not user-friendly, people won't use it properly.

A straightforward experience reduces the urge to bypass the system.

Choose a solution that fits well with how your teams already work.

That makes adoption easier.

Read our full review of the best secure email services.

Securing Your Emails - Essential to Business Operations?

Cyber threats are on the rise, from phishing to human error.

Strong data protection laws mean the stakes are higher than ever.

Investing in a capable secure email tool is crucial for modern business.

By choosing a solution with reliable encryption, identity checks, and a simple interface, you can protect sensitive data and meet your legal obligations.

You'll maintain your reputation and give both colleagues and clients peace of mind.

Securing your emails is a proactive way to support safer digital communications.

FAQs

What Is Secure Email?

Secure email is email protected with additional controls such as encryption, recipient authentication, secure replies, and audit evidence.

Who Is Secure Email For?

It is useful for organisations that send personal data, financial information, legal documents, or confidential business material.

What Should Secure Email Protect Against?

It should reduce exposure from interception, misdelivery, unauthorised access, insecure replies, and loss of control after sending.

References

51 Must-Know Phishing Statistics for 2023, IT Governance, 2023

Cost of a Data Breach 2023: Financial Industry Impacts, Security Intelligence, 2023

Cyber Security Breaches Survey 2024, UK Government, 2024

Data Security: An Analysis of 2022 ICO Breach Reporting, Beyond Encryption, 2023

The Devastating Business Impacts of a Cyber Breach, Harvard Business Review, 2023

‘Psychology of Human Error’ Could Help Businesses Prevent Security Breaches, CISO Mag, 2020

Reviewed by

Sam Kendall, 02.06.26

Sabrina McClune, 19.12.24

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