What is Email Interception?

Did you know that a single intercepted email could expose sensitive data and disrupt your business?

Email interception and unauthorised access are growing cybersecurity threats that can expose sensitive information to the wrong people.

Understanding how messages get exposed - and using secure email practices, especially encryption - is crucial for protecting your communications.

"In my 40 years in digital security, I've seen how a single lapse in email security can have serious consequences. Protecting your communications from interception is essential."

Paul Holland, Founder, Beyond Encryption

Email interception threats can include man-in-the-middle attacks, as well as phishing-led account takeovers and compromised accounts.

By combining email encryption with strong authentication, you can reduce the risk of email interception and better protect sensitive communications.

Contents

• What Is Email Interception?
• Risks Associated with Interception
• Protecting Against Interception
• Why Encrypt Attachments?
• How to Encrypt Attachments
• Email Interception: The Crux

What Is Email Interception?

Email interception happens when unauthorised individuals gain access to email communications as they travel across networks, often without the sender's or recipient's knowledge.

This kind of breach allows threat actors to eavesdrop on private conversations and potentially modify email contents.

Interception can occur at various points along the email's journey, including within the sender's or recipient's email servers, during transit over the internet, or at any intermediate servers handling the email.

"Many people underestimate how easily emails can be intercepted during transmission. Understanding where vulnerabilities lie is the first step in securing your communications."

Mike Wakefield, CTO, Beyond Encryption

How Can Emails Be Exposed?

Attackers use different tactics to intercept messages or gain unauthorised access to email accounts:

Man-in-the-Middle Attacks

Attackers position themselves between the sender and recipient to intercept or alter email content.

They can read, modify, or delete messages, sometimes without being noticed.

Phishing and Spoofing

Criminals can impersonate trusted sources to trick recipients into sharing sensitive data.

They may send emails that appear legitimate to obtain passwords or financial information.

Spy Pixels

Invisible tracking pixels can be used to monitor email opens and gather recipient data, creating a privacy risk.

They can reveal when an email is read and, in some cases, general location or device details - even though they do not intercept the message content.

Risks Associated with Email Interception

Email interception can pose serious risks.

Email is one of the most widely used communication tools.

The problem is that email standards were not originally designed with modern security threats in mind.

As more sensitive information gets shared by email, the risks associated with interception increase.

Applying the security measures above can help protect personal data, financial information, and support compliance efforts.

Financial Fraud

Attackers can modify financial details in intercepted emails, leading to fraudulent transactions.

This can result in monetary losses for individuals and businesses.

"We've seen companies suffer huge financial losses due to intercepted emails altering payment details. Implementing strong security measures isn't just about compliance - it's about protecting your bottom line."

Adam Byford, CCO, Beyond Encryption

Data Breaches and Reputational Damage

Exposing confidential data can result in legal and reputational harm, as we highlight in our ICO findings analysis.

Organisations can face both financial penalties and loss of customer trust.

"In the financial services industry, secure communication isn't just about protecting data - it's about maintaining trust with your clients."

Carole Howard, Head of Networks, Beyond Encryption

Identity Theft

Intercepted data can enable cyber criminals to carry out unauthorised transactions and impersonate people.

Personal information can be used to commit fraud or other malicious activities.

How to Protect Against Email Interception

Using robust security measures can reduce the risks of interception.

Cybersecurity professionals often recommend strategies like:

End-to-End Encryption

Email encryption helps make sure only the intended recipient can read the content, making it unreadable to unauthorised parties who obtain a copy.

End-to-end encryption standards such as S/MIME (Secure/Multipurpose Internet Mail Extensions) or OpenPGP can protect both the body of an email and attachments.

These approaches typically use strong encryption algorithms (for example AES-256, part of the Advanced Encryption Standard family) to protect message content.

"End-to-end encryption is one of the most effective tools we have against email interception. It's becoming increasingly essential for both businesses and individuals."

Mike Wakefield, CTO, Beyond Encryption

Encrypting Email Attachments

Encrypting attachments adds an extra layer of protection.

It helps make sure that even if an email is intercepted or accessed later, the attachments are unreadable without the right decryption keys.

Two-Factor Authentication (2FA)

Two-factor (or multi-factor) authentication makes it harder for attackers to gain access to emails even if a user's credentials are stolen.

It asks people to provide two forms of identification before accessing an account (e.g., a password and a code sent to their phone).

Verify Sender Identity

Manually verifying that financial or sensitive instructions come from a trusted source can help prevent phishing and spoofing.

Use a known, independent channel (for example, a phone call to a verified number in your directory) rather than replying to the email thread.

Regular Security Protocol Updates

Organisations should keep email servers and clients patched and make sure transport encryption (TLS/STARTTLS) is enabled and enforced where possible.

Regular updates can patch vulnerabilities that could be exploited.

User Education

Training users (or yourself) to recognise phishing emails and understand secure email practices can reduce the risk of interception.

Educated users are less likely to fall for social engineering attacks.

"User education is often overlooked but is critical in preventing email interception. An informed team is your first line of defence against threats."

Emily Plummer, Marketing Director, Beyond Encryption

Why Encrypt Attachments?

Sending email attachments without encryption can leave documents open to risk.

It's like writing your personal information on a postcard - anyone who handles it can read its contents.

For individuals and organisations dealing with sensitive information, encryption is an important part of a strong cybersecurity strategy.

When you encrypt email attachments, you scramble the information, making it unreadable to unauthorised parties without the right keys.

This can really reduce the risk of email interception and support compliance with privacy laws and regulations.

How to Encrypt Attachments

Encrypting email attachments is important for keeping sensitive documents confidential.

Here's how to encrypt attachments in popular email clients (note that exact steps can vary by organisation settings and account type):

Encrypt Email Attachments in Outlook

• Compose a new email and attach your files.
• Go to the "Options" tab and select "Encrypt" or "Security Settings" (if available).
• Choose the encryption settings that suit your needs.
• Send the email as usual.

Protect Attachments in Gmail (Confidential Mode)

Gmail's Confidential Mode can help limit access, but it is not the same as end-to-end attachment encryption.

• Compose a new email and attach your files.
• Select the lock/clock option to turn on "Confidential mode".
• Set an expiry date and add a passcode requirement if needed.
• Send the email.

Encrypt Email Attachments in iOS Mail (S/MIME)

• Make sure your organisation supports S/MIME and you have a certificate installed for your email account.
• In Settings, enable S/MIME for the relevant mail account (where available).
• Compose your email and attach your files as normal.
• Check that encryption is enabled (often shown with a lock indicator) before sending.

To view the full instructions, read How to Encrypt Email Attachments.

What Are the Consequences of Failing to Protect Emails?

Failing to secure email communications can lead to serious consequences:

• Financial Losses: Due to fraud or theft resulting from exposed information.
• Legal Penalties: Non-compliance with data protection regulations can result in significant fines.
• Reputational Damage: Loss of customer trust and business opportunities.

According to the Cyber Security Breaches Survey 2023, 32% of UK businesses reported a cybersecurity breach or cyber attack in the past 12 months, highlighting the importance of robust email security.

Email Interception: The Crux

Email interception is a real risk in our digital world.

If you combine encryption and authentication with regular updates and training, you can reduce these risks and better protect your communications.

Encrypting email attachments is especially important for safeguarding confidential documents.

Being proactive in your approach to email security and staying aware of common threats can help keep important data safer.

FAQs

What Does Intercepting Emails Mean?

Email interception occurs when unauthorised individuals access, modify, or delete emails during transmission or while stored on servers, often without the sender or recipient realising.

How Do You Know If Your Emails Are Being Intercepted?

Signs include unusual account activity, emails marked as read without your action, or unauthorised changes to settings - monitoring these can help you spot issues early.

What Are the Risks of Email Interception?

Risks include financial fraud, data breaches, identity theft, and reputational damage, as attackers can alter transactions or steal sensitive information.

How Do People Intercept Emails?

Methods can include man-in-the-middle attacks, phishing-led credential theft, and account compromise.

Spy pixels do not intercept email content, but they can track opens and leak metadata about when an email was viewed.

Can Unencrypted Emails Be Intercepted?

Yes.

Without end-to-end encryption, email content may be readable at different points in the delivery chain (for example, on servers or endpoints).

Transport encryption (such as TLS/STARTTLS) can protect messages in transit, but it does not provide end-to-end protection on its own.

Can I Tell If Someone Is Tracking My Email?

Some emails can include tracking pixels that report when an email is opened.

Disabling automatic image loading and using privacy or tracking protections can reduce this, though it may not stop all tracking methods.

Is Interception a Security Threat?

Yes, email interception can contribute to data loss, fraud, and operational disruptions, which is why layered security measures matter.

Will Changing My Email Password Stop Hackers?

Changing your password helps, but you may need further steps, like enabling two-factor authentication, if malware or other access exists.

References

Email Interception, Guardian Digital, 2022

Data Security: An Analysis of ICO Findings, Beyond Encryption, 2023

Spy Pixels, Wikipedia, 2024

Are Your Emails Being Intercepted? Fight Email Fraud, Debra R Richardson, 2023

Phishing, The Information Commissioner's Office (ICO), 2024

Reviewed by

Sabrina McClune, 26.11.24

Sam Kendall, 15.11.24