What Is an Email Security Gateway and Why You Need One

What Is a Secure Email Gateway (SEG)?

A secure email gateway (SEG) is a network security solution that monitors and protects an organization’s email communications from threats such as spam, phishing, malware, and data leaks. It helps organizations safeguard their sensitive information, maintain regulatory compliance, and reduce the risk of cyberattacks.

SEG acts as an intermediary between the organization’s email infrastructure and the internet, scanning incoming and outgoing messages for malicious content and applying filtering rules, encryption, and authentication to ensure the confidentiality, integrity, and availability of email data. 

What Threats Can SEGs Protect Against?

SEGs can protect against the following threats:

• Spam: SEGs use advanced filtering techniques and algorithms to identify and block spam emails, reducing the volume of unsolicited messages that reach users’ inboxes.
• Phishing and spear-phishing attacks: SEGs analyze email content, sender information, and other factors to identify and block phishing attempts, minimizing the risk of users falling victim to scams or credential theft.
• Malware: SEGs scan all incoming and outgoing emails for malicious attachments, links, or embedded content. They block, quarantine, or remove potentially harmful content to prevent malware infections, such as viruses, ransomware, and trojans.
• Business Email Compromise (BEC): SEGs can detect and prevent BEC attacks, in which cybercriminals impersonate executives or other trusted individuals within an organization to manipulate employees into transferring funds or revealing sensitive information.
• Email spoofing: SEGs can verify the authenticity of email senders using technologies such as SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting, and Conformance) to prevent email spoofing and protect against impersonation attacks.
• Data Loss Prevention (DLP): SEGs can help organizations prevent sensitive information from being accidentally or intentionally leaked via email by scanning outgoing emails for specific data patterns, keywords, or classifications and taking appropriate action, such as blocking or encrypting the email.
• Email-based Denial of Service (DoS) attacks: SEGs can protect against email-based DoS attacks, such as email bombing or email flooding, by monitoring and throttling email traffic to maintain the availability and performance of the email infrastructure.
• Insider threats: By monitoring and analyzing email traffic, SEGs can help organizations detect potential insider threats, such as employees attempting to exfiltrate sensitive data or engage in other malicious activities.

By deploying a secure email gateway, organizations can protect their email communications from various security threats, maintain the confidentiality and integrity of sensitive information, and comply with relevant regulations and policies.

Main Features Of A Secure Email Gateway

A secure email gateway has several main features:

Spam filtering 

Spam filtering involves detecting and filtering out unsolicited and unwanted emails, commonly referred to as spam. SEGs use various techniques to achieve this, such as analyzing email content, checking for known spam signatures, and using machine learning algorithms to identify patterns and characteristics of spam emails. 

SEGs may also maintain lists of trusted and blocked senders or use reputation-based systems to assess the legitimacy of the email source. By filtering out spam, SEGs not only reduce clutter in users’ inboxes but also minimize the risk of phishing attempts or malware-laden emails.

Virus and malware detection 

Email is a common attack vector for malware, which can be delivered through attachments, embedded links, or even the body text of the email. SEGs scan all incoming and outgoing emails for known malware signatures, heuristics, or suspicious behavior patterns. 

Advanced SEGs may use sandboxing techniques to analyze attachments and URLs in a secure environment, simulating their behavior to identify potential threats. This helps protect the organization from malware infections, which could lead to data breaches, system disruptions, or other security incidents.

Data loss prevention (DLP) 

DLP helps organizations prevent the unauthorized sharing or leakage of sensitive data via email. SEGs can be configured with predefined policies to detect and block emails containing specific keywords, patterns, or sensitive data such as credit card numbers and social security numbers.

These policies are often designed to comply with regulatory standards like GDPR, HIPAA, or PCI-DSS. The SEG can either block the email or alert the security team, depending on the organization’s preference.

Email encryption 

Email encryption is a security measure that ensures the confidentiality of email content as it travels over the internet. SEGs can encrypt emails using various encryption standards, such as S/MIME, PGP, or TLS, to protect sensitive information from being intercepted by unauthorized parties. 

Emails can be encrypted at rest (when stored on servers) and in transit (when being sent between email servers or clients). Email encryption helps organizations maintain compliance with data protection regulations and prevent unauthorized access to sensitive information.

Policy enforcement 

SEGs enable organizations to define and enforce email usage policies, which help maintain a secure email environment and comply with internal and external regulations. These policies can range from controlling the type and size of email attachments to filtering emails based on keywords or content. 

SEGs can be configured to block, quarantine, or redirect non-compliant emails, and notify administrators or users about policy violations. Policy enforcement helps organizations maintain a consistent approach to email security and reduces the risk of human error or policy violations.

How to Choose a Secure Email Gateway Solution?

Choosing the right secure email gateway solution for your organization is crucial for effectively protecting against email-based threats. Here are some factors to consider when selecting an SEG solution:

• Compatibility: Ensure the SEG solution is compatible with your organization’s email infrastructure, whether it’s on-premises, cloud-based, or a hybrid environment. Check for compatibility with your email server, operating system, and other components of your IT infrastructure.
• Deployment options: SEG solutions can be deployed as hardware appliances, virtual appliances, or cloud-based services. Determine which deployment option best suits your organization’s needs in terms of scalability, cost, and maintenance requirements.
• Security features: Evaluate the security features offered by the SEG solution, such as spam filtering, malware protection, phishing prevention, DLP, and email encryption. Look for advanced technologies like machine learning, behavior analysis, and sandboxing to ensure comprehensive protection against emerging threats.
• Integration: Check if the SEG solution can be easily integrated with your organization’s existing security tools, such as antivirus software, firewalls, and SIEM systems. Seamless integration ensures better visibility and coordinated defense against threats.
• Performance and scalability: Consider the SEG solution’s impact on email performance and its ability to scale with your organization’s growth. Look for solutions that minimize email processing delays and can handle increasing email volumes without compromising security.
• Compliance requirements: If your organization is subject to specific regulatory or industry requirements, make sure the SEG solution helps you meet those requirements. Features like email encryption, DLP, and email archiving may be essential for compliance with certain regulations.

By considering these factors and carefully evaluating different SEG solutions, you can choose the one that best meets your organization’s needs and provides comprehensive protection against email-based threats.

Conclusion

Secure email gateways (SEGs) help organizations protect their email communications from a wide range of threats, such as spam, phishing, malware, and data leaks. When choosing an SEG solution, consider your organization’s specific needs, evaluate potential vendors, and test solutions before implementation. Implementing an SEG is critical for maintaining a robust security posture and safeguarding sensitive information.-

Author Bio: Gilad David Maayan

Gilad David Maayan is a technology writer who has worked with over 150 technology companies including SAP, Imperva, Samsung NEXT, NetApp and Check Point, producing technical and thought leadership content that elucidates technical solutions for developers and IT leadership. Today he heads Agile SEO, the leading marketing agency in the technology industry.

LinkedIn: https://www.linkedin.com/in/giladdavidmaayan/