What exactly is a Secure Email Gateway (SEG)?
Secure Email Gateways, often known as SEGs, are a kind of email security solution that works in conjunction with corporate email servers to protect communications as they travel from the public Internet to those servers. Because of its location, it is able to examine incoming email for potentially harmful information before it reaches the corporate servers. The structure of the SEG, on the other hand, makes it less suitable for the protection of contemporary email systems that are hosted on the cloud.
What is the operation of a Secure Email Gateway?
An SEG accomplishes its tasks by functioning as a proxy for the email server of an organisation. During the process of setting a SEG, the organisation modifies its DNS MX record so that it points to the cloud-based proxy that is associated with the SEG. After then, every email that was sent to the organisation would be routed to the proxy that the SEG uses.
After then, the SEG may filter and examine the email to look for dangerous material depending on the threat intelligence it has received. After the email has been cleaned up, the SEG will send it on to the corporate email server so that it may be sent to the person who it was meant for.
Principal Characteristics of a Safe Email Gateway
An SEG is designed to provide full protection against dangers that might be sent by email. The following are some of the most important aspects of a SEG:
The term "Material Disarm and Reconstruction" (CDR) refers to the process by which harmful content is removed from email attachments. CDR will deconstruct these files, remove any harmful material from them, and then reconstruct a clean version of the file so that it may be sent to the user.
Sandboxing: When analysing certain samples, particularly zero-day threats, it may be difficult to determine if email attachments and URLs are harmless or dangerous. Sandbox analysis makes it possible to evaluate this information in an environment where harmful code may be run and investigated without putting the company at risk.
Data Loss Prevention (DLP): Because email is intended to be used for the exchange of information, it presents a unique opportunity for the theft of data. DLP systems are able to recognise intellectual property (IP) as well as data that is governed by rules inside emails and prohibit this information from being sent to unauthorised parties or in a manner that is not safe.
Phishing is one of the most prevalent cyber dangers and has the potential to be exploited for the transmission of malware, the theft of credentials, and the exfiltration of data. Anti-Phishing: An anti-phishing defence should be included into a SEG so that it can detect and prevent dangerous links and attachments contained inside an email.
Protection After Delivery: During the inline examination of emails, a SEG may not find all dangers, particularly when dealing with zero-day threats. This is why post-delivery protection is important. Post-Delivery Protection is able to remove harmful emails from the user's inbox by integrating APIs with the user's email provider. This email may have already been opened by the user, which means that a security warning on a possible intrusion is generated as a result.
Domain-Based Message Authentication, Reporting, and Conformance (DMARC): DMARC was developed to guard against spoofing of email addresses from domains that have enabled it. Any email that does not pass the DMARC test and originates from a domain that has this protection enabled should be blocked by a SEG.
Why Is It Important to Have a Secure Email Gateway?
Attacks that are carried out through email pose a significant challenge to the cybersecurity of businesses. Phishing is one of the most prevalent vectors for cyberattacks and may be used to acquire sensitive information as well as distribute malware. An attacker may get access to important data and other online accounts via a hacked email account's ability to send and receive emails.
The purpose of a SEG is to provide a much-required extra layer of security against phishing and other risks that may be sent over email. Due to the deficiencies of the built-in security solutions found in many email systems, risk management absolutely requires using a defense-in-depth strategy.
The Limits That Secure Email Gateways Have To Offer
When corporate email was predominantly stored on-premises, SEGs were among the most effective methods available for ensuring its safety. SEGs have attempted to adapt to the changing environment; nevertheless, their efforts have been unsuccessful because to the growing prevalence of cloud-based email systems among businesses. SEGs have a number of significant drawbacks for use in today's businesses, including the following:
Perimeter-Focused Protection: Many SEGs will analyse incoming email traffic that is routed to the corporate email server by first routing it via a cloud-based proxy. This is done before sending the email to its final destination. Despite the fact that this protects the solution from external dangers, it does little to address the dangers that come from inside.
Single-Layer Security: Certain SEGs are capable of disabling the inbuilt security safeguards provided by an email service (Google, Microsoft, etc.). This reduces the need for several layers of security, making an organisation more susceptible to assault.
Email Protection: SEGs are developed specifically to provide protection for email and only email. However, since these new cloud-based file sharing and collaboration technologies are not as secure as their predecessors, businesses who use them leave themselves open to cyberattacks from unsecured services.
Poor OPSEC: In order to allow some SEGs, it is essential to alter the DNS MX record of an organisation so that it points to the proxy. The disclosure of the email security solution that is being used gives attackers the ability to adapt their assaults so that they may bypass defences.
Root Domains: While a company may have its DNS MX record referring to its SEG, both Office 365 and G Suite have a root domain whose DNS is handled by either Microsoft or Google. This is in contrast to the situation in which an organisation may have its DNS MX record link to its SEG. Attackers that send emails to this root domain are able to get through a SEG's protections.