What Is an Email Encryption Gateway?

An email encryption gateway is an essential tool for securing a business’ enterprise email communications. It makes sure sensitive information is protected from unauthorised access by encrypting it before it is sent to external recipients.

By providing robust security, seamless integration, and compliance support, email encryption gateways have become indispensable for businesses in safeguarding data and building trust.

Email encryption gateways are a key component of a strong outbound email security strategy.

They are used to encrypt emails between your organisation and external parties, protecting the confidentiality and integrity of message content as it passes over unencrypted channels.

Having been in cybersecurity for years, I have seen firsthand how businesses struggle to secure their email communications effectively.

Email encryption gateways offer a practical solution to these challenges, making sure sensitive information stays protected.

As well as providing email security, encryption gateways help with regulatory compliance, making sure that sensitive information isn't leaked during transmission or stored without appropriate protection.

Some email encryption gateways are hosted on-premise and managed by internal company administrators.

Other gateway solution providers offer a fully managed service run on cloud-based technology.

Email encryption gateways should integrate with existing email systems, enhancing security without disrupting everyday email usage.

They are adaptable to various email platforms, maintaining user experience while adding a layer of protection.

Gateways should include strong encryption protocols and recipient verification processes, making sure that sensitive information remains confidential and is accessible only to the intended recipients.

It’s important to consider that some email encryption gateways might introduce a degree of user inconvenience.

Recipients who are not familiar with the chosen encryption solution might need to take additional steps to access encrypted emails.

Additionally, compatibility issues can arise if recipients lack compatible software to decrypt messages.

Research shows ease of use is incredibly important when selecting an email encryption solution, to experience and security.

Inbound vs. Outbound

Email encryption gateways can play two different functions, addressing both common user concerns and specific needs:

Outbound email encryption gateways encrypt communications on delivery, securing messages sent to anyone outside your security infrastructure.

This can include customers, partners, vendors, or staff working remotely.

When you send an email to someone outside your company infrastructure, only the intended recipient should be able to decrypt it.

This makes sure that sensitive information is protected from falling into the wrong hands.

Inbound email encryption gateways can:

• Keep incoming encrypted emails secure; making sure they stay protected until the intended recipient accesses them.
• Decrypt incoming encrypted emails so that the intended recipients can read them and download any attachments.

In many cases, organisations will configure their inbound email encryption gateway to only allow emails from certain senders using a whitelist.

This gives administrators control over the emails that enter their company's infrastructure and helps to reduce email phishing.

On-Premise vs. Cloud

Companies can choose to host email encryption gateway software on their server or their gateway vendor's server.

Each option offers distinct advantages based on user needs.

On-premise deployments grant organisations complete control over their infrastructure, making them ideal for businesses with stringent regulatory requirements or data sovereignty concerns.

This ensures compliance and allows businesses to manage data entirely within their own environments.

Cloud deployments, on the other hand, are often chosen for scalability and efficiency.

They are especially suited for businesses looking to minimise overhead costs and benefit from provider-managed infrastructure and ongoing updates.

Cloud solutions can also be more adaptable for organisations experiencing rapid growth.

Regardless of the deployment type, most gateway vendors offer or support integrations with major mail exchange servers including Exchange, Office 365, G Suite, and IBM Domino.

"Email encryption is not just a compliance tool; it's a trust-builder for businesses navigating today's digital landscape."

— Paul Holland, Founder, Beyond Encryption

There are several well-regarded secure email services on the market.

Consider factors like budget, deployment needs (cloud vs. on-premise), ease of use, and integrations with your existing email infrastructure when making a selection.

If you choose the right email encryption gateway, it should be able to handle high volumes of emails without sacrificing performance, making it suitable for businesses as they grow their customer base.

Does Microsoft 365 Provide an Email Encryption Gateway?

Microsoft 365 does not offer a dedicated email encryption gateway, though it is able to encrypt outbound and decrypt inbound encrypted messages in a limited capacity.

Emails encrypted using M365's native email encryption, Microsoft Purview Message Encryption (MPME), can be decrypted into the inboxes of Microsoft Outlook users.

However, emails secured in this way can be difficult for users of other email providers or legacy Outlook users to access.

Microsoft's encryption algorithm has also been questioned, leading the company to make a statement that its email encryption should "not be used as a security boundary".

Learn more about Microsoft 365's secure email capability.

Email Encryption Gateways: A Vital Defence for Data

In today's digital age, prioritising email security is not an option; it's a non-negotiable element of protecting your business and its valuable data.

Email encryption gateways are a vital investment for businesses.

They safeguard sensitive data, mitigate security risks, ensure compliance with data regulations, and foster trust.

FAQs

What Is an Email Encryption Gateway?

An email encryption gateway is a tool that encrypts and decrypts email communications to secure sensitive information.

How Does an Email Encryption Gateway Work?

The gateway encrypts email content before it is sent to recipients and makes sure that only authorised recipients can decrypt it.

What Are the Benefits of Using Email Encryption Gateways?

They enhance email security, ensure regulatory compliance, and protect sensitive information during transmission.

What Should I Look for in an Email Encryption Gateway?

When choosing an email encryption gateway, consider factors like ease of integration with existing systems, compliance with relevant regulations, the robustness of encryption protocols, scalability, and user-friendliness.

You should also evaluate the provider’s customer support and the cost-effectiveness of their solution.

References

Usability of End-to-End Encryption in E-Mail Communication, Frontiers in Big Data, 2021 https://www.frontiersin.org/articles/10.3389/fdata.2021.568284/full

E-Mail Message Encryption Using Advanced Encryption Standard (AES) and Huffman Compression, International Conference on Computer Science and Software Engineering, 2020

Microsoft Office 365 Message Encryption Should Not Be Used as a Security Boundary, The Register, 2022.

Securing Enterprise Email Communication on Both Sides of the Firewall, Springer Link, 2015.

Reviewed by

Sabrina McClune, 23.12.24

Sam Kendall, 23.12.24