Email Security Explained Like Airport Security

Email remains one of the most effective channels for business communication. Not surprisingly, it is also one of the most common attack vectors for cyber threats.

So how does email security work?

To better understand what might be the most effective way to keep criminals out of your inbox, let’s break down the email delivery process into two stages: pre-delivery and post-delivery.

You need email protection for both stages of the delivery process.

First I’ll break down the technical challenge and then I’ll try to explain it by using the analogy of airport security, which is something most of us can relate to.

Pre-delivery catches most but not all

While secure email gateways (SEGs) play a crucial role in your organization’s email security strategy, relying solely on this initial line of defense is no longer sufficient. Secure email gateways are designed to scan incoming and outgoing emails for known threats, such as malware, spam, and phishing attempts, before they reach your organization’s network. While SEGs are effective at blocking a significant portion of these threats, they have inherent limitations:

1. Signature-Based Detection

SEGs primarily rely on signature-based detection, which means they can only identify threats that have been previously encountered and have a known signature. This approach struggles to keep up with the ever-evolving nature of cyber threats, leaving your organization vulnerable to new and emerging threats that have yet to be cataloged.

2. Static Analysis

SEGs typically perform static analysis on emails, which means they analyze the content of an email at a specific point in time. However, many modern threats are designed to evade this type of analysis by hiding their malicious behavior until after the email has been delivered and opened.

3. Limited Visibility

SEGs have limited visibility into the broader context of an email’s content and the recipient’s behavior, making it challenging to detect more sophisticated threats that may appear innocuous at first glance.

The Power of Post-Delivery Cloud App Security

Post-delivery cloud app security solutions provide an additional layer of protection by continuously monitoring and analyzing emails even after they have been delivered to your organization’s network. These solutions leverage advanced techniques, such as machine learning and behavioral analytics, to identify and mitigate threats that may have slipped past the secure email gateway.

Here are some key advantages of post-delivery cloud app security:

1. Advanced Threat Detection

Post-delivery solutions employ advanced techniques, such as sandboxing and dynamic code analysis, to detect and analyze potential threats that might have evaded initial detection. This allows for the identification of previously unknown or emerging threats, providing a proactive defense against zero-day attacks.

2. Continuous Monitoring

Unlike SEGs, which provide a single point-in-time analysis, post-delivery solutions continuously monitor emails and user interactions, enabling them to detect and respond to threats that may manifest after delivery.

3. Contextual Analysis

By analyzing the broader context of an email, including the sender’s reputation, the recipient’s behavior, and the email’s content and attachments, post-delivery solutions can identify sophisticated threats that may appear benign at first glance.

4. Automated Remediation

In the event of a detected threat, post-delivery solutions can automatically quarantine or remove the malicious email from your organization’s network, minimizing the risk of further compromise and reducing the burden on your security team.

Implementing a Comprehensive Email Security Strategy

In our work as a [Managed Cybersecurity Provider](https://impactgroupmn.com/cybersecurity/) I sometimes need to explain to non-technical business leaders the necessity of needing both secure email gateways and post-delivery scanning. Let’s use the analogy of an airport’s security system, which combines multiple layers of security checks to ensure the safety of passengers and flights.

Think of the secure email gateway as the airport’s initial security screening process. Every passenger (email) must go through this screening, which is designed to catch and prevent dangerous items (threats) from getting any further. This initial checkpoint is highly effective and stops the majority of prohibited items. However, just as in an airport, no screening process is infallible. Some items might be so well-disguised or novel that they pass through this initial checkpoint unnoticed.

That’s where the concept of post-delivery scanning and filtering comes into play, similar to an airport’s ongoing security measures, including surveillance, behavior analysis, and random checks after passengers have passed through the initial security screening. In our analogy, this represents the security systems that continuously monitor the inside of the airport (the network) and the behavior of passengers (email interactions) even after they’ve passed the initial check.

If a passenger begins to act suspiciously or if a previously unnoticed threat is identified, airport security can quickly intervene, isolating the passenger for further investigation or taking necessary actions to neutralize the threat. This is akin to post-delivery email security measures, where emails, even after being delivered, are continuously analyzed for malicious content or behavior that was not detected at the initial screening. If something dangerous is discovered after delivery, these systems can quarantine the email, preventing any potential harm.

This layered approach to security, combining both pre-boarding checks (secure email gateways) and in-terminal surveillance (post-delivery scanning and filtering), ensures that even if a threat slips through one layer of security, additional layers are in place to catch and mitigate it.

To effectively protect your organization against the ever-evolving threat landscape, it is essential to adopt a multi-layered approach that combines the initial protection of a secure email gateway with the advanced detection and continuous monitoring capabilities of post-delivery cloud app security solutions.

By leveraging the strengths of both technologies, you can significantly reduce your organization’s risk exposure and enhance your overall email security posture.

*George Bakalov is a Certified vCISO and the Director of Cybersecurity at IMPACT Group, a Minneapolis-based Managed IT Services Provider.*