Last Updated: Wednesday July 12, 2023

As email continues to dominate the corporate communications landscape, it’s no surprise that businesses are increasingly targeted by cybercriminals seeking to exploit vulnerabilities. Secure email gateways (SEGs) have emerged as a critical line of defense in this ongoing battle, functioning as an essential component of a robust corporate mail gateway strategy.

A secure email gateway is a solution that scrutinizes emails as they are sent and received, filtering out unwanted messages such as spam, phishing attempts, malware or fraudulent content and ensuring that only legitimate emails reach the intended recipient.

The significance of SEGs in modern business operations is undeniable, as they provide a protective barrier against unauthorized transmission of sensitive data and help companies avert the costly repercussions of data breaches. Let’s take a closer look at the benefits and features of Secure Email Gateways and the vital role SEGs play in safeguarding corporate email communications.

What Is a Secure Email Gateway?
Key Features of Secure Email Gateways
Shortcomings of Secure Email Gateways
How Secur-Serv’s Email Security Services Address SEG Shortcomings

What Is a Secure Email Gateway?

A Secure Email Gateway is a kind of email server designed to fortify an organization’s email environment. Acting as a gateway, SEGs ensure that all inbound and outbound emails are thoroughly scanned, effectively counteracting email-based threats before they can infiltrate email servers, regardless of whether they are hosted on-premises or rely on cloud-based email clients such as Microsoft Office 365 or G-Suite.

SEGs offer several advantages, including:

  • Preventing malicious emails and thwarting phishing attacks
  • Stopping unauthorized dissemination of sensitive information
  • Safeguarding employee emails across various devices
  • Adhering to compliance regulations through email archiving and encryption

How SEGs Work in Practice

SEGs meticulously examine all internal, inbound and outbound email exchanges, searching for indications of harmful URLs, attachments or content. By isolating and discarding emails containing dubious elements, SEGs provide a robust defense against social engineering attacks such as phishing and business email compromise (BEC). Certain systems also offer administrators the option to access emails placed in quarantine when needed.

Real-World Examples of SEGs in Action

  • A company uses an SEG to prevent phishing attacks by blocking suspicious emails and attachments, reducing the risk of data breaches and cyber-attacks.
  • A financial institution employs an SEG to protect sensitive customer information by scanning incoming and outgoing emails for signs of data loss, such as credit card or Social Security numbers.
  • A healthcare provider utilizes an SEG to comply with regulatory requirements and protect patient data by filtering out emails containing sensitive medical information.
  • A manufacturing company relies on an SEG to prevent malware and ransomware attacks by automatically sandboxing suspicious emails and attachments, minimizing the impact of potential cyber-attacks.
  • A law firm implements an SEG to filter out spam and unwanted emails, allowing its employees to focus on important communications and reducing the risk of email overload and burnout.

Key Features of Secure Email Gateways

SEGs come equipped with various features to enhance email security. Let’s explore some of those key features, along with their advantages and disadvantages.

Content Disarm & Reconstruction (CDR)

CDR is a security feature that neutralizes potentially harmful elements in documents.


  • Removes potentially malicious code from documents and reconstructs the files with known-safe elements, enabling access to the content without risking infection


  • May cause formatting changes in reconstructed documents and may not always catch every threat, especially if it’s a new or unknown type


Sandboxing is a technique that isolates and tests suspicious files or links in a safe environment.


  • Quarantines questionable files or links in a secure environment, enabling the system to analyze their behaviors without risking the organization’s network


  • Some advanced threats can detect when they’re being analyzed in a sandbox and alter their behavior to avoid detection

Data Loss Prevention (DLP)

DLP is a feature that monitors and prevents sensitive data from being sent outside the organization.


  • Screens and stops sensitive information from being sent outside the organization, helping avoid data breaches and maintain regulatory compliance


  • Can sometimes result in false positives, blocking legitimate emails or causing delays in communication

Anti-Phishing & Anti-Spam Filters

These filters are designed to identify and block phishing, spam and other unwanted emails.


  • Help recognize and stop phishing attacks, spam and other unwanted emails, reducing the risk of successful attacks and decluttering inboxes


  • May sometimes block legitimate emails or fail to catch all phishing or spam messages, especially if the attackers use new tactics or techniques

Email Encryption

This feature encrypts emails to protect sensitive information from unauthorized access during transit.


  • Ensures that sensitive data remains secure during transmission, enhancing privacy and complying with industry-specific standards


  • Can be a complex and time-consuming process, and not all email clients or recipients support encrypted emails

Email Archiving

With email archiving, emails are stored and indexed to ensure compliance with regulations and to provide easy access to historical email data.


  • Ensures regulatory compliance for data retention and e-discovery and enhances the main email system’s performance, resulting in faster loading times and reduced server strain


  • Can be costly and may necessitate additional investments in infrastructure or cloud storage services

Shortcomings of Secure Email Gateways

While SEGs are a valuable tool for email security, they do have certain limitations and can be bypassed or exploited. Understanding these shortcomings is essential to implementing a comprehensive email security strategy.

Limitations of SEGs

  • False positives: SEGs may incorrectly flag legitimate emails as malicious, causing disruptions in business communications and potentially damaging relationships with clients or partners.
  • Advanced threats: Cybercriminals are constantly evolving their tactics, and some advanced threats may slip past SEG defenses.
  • Complex deployment: Implementing and integrating SEGs into an organization’s email infrastructure can be challenging and time-consuming, especially for those without in-house IT expertise.
  • Cost: The expense of purchasing, deploying and maintaining SEGs can be a burden for some organizations, particularly smaller ones or those with limited budgets.
  • Maintenance: Regular updates and maintenance are required to keep SEGs effective, which can be resource-intensive and may necessitate ongoing IT support.

Ways in Which SEGs can be Bypassed or Exploited

  • Social engineering: Skilled attackers may craft highly convincing phishing emails that evade detection by SEGs, tricking recipients into divulging sensitive information or executing malicious actions.
  • Malware obfuscation: Cybercriminals can use various techniques to hide the true nature of malicious attachments or links, enabling them to bypass SEG filters.
  • Email spoofing: Attackers may force email headers to impersonate trusted senders, potentially deceiving SEGs and recipients alike.
  • Encrypted traffic: Encrypted email content can sometimes bypass SEG detection, as the gateway may not be able to inspect the contents of encrypted messages.
  • Zero-day exploits: New vulnerabilities and exploits that have yet to be identified or patched may be used to bypass SEG defenses.

Additional Measures to Consider for Comprehensive Email Security

To address the limitations of SEGs and create a more robust email security strategy, consider implementing the following additional measures.

  • Employee training: Educate employees on how to recognize phishing emails, spam and other malicious communications to reduce the likelihood of successful attacks.
  • Multi-factor authentication: Implement multi-factor authentication to add an extra layer of security, making it more difficult for attackers to access email accounts even if they obtain login credentials. Check out our resource on selecting secure passwords.
  • Advanced threat detection: Employ advanced threat solutions that use AI and machine learning to identify and respond to evolving threats more effectively.

Address Email Threats with Secur-Serv’s Email Security Services

In the ever-evolving world of cybersecurity, organizations must prioritize continuous employee education to reduce the risk of successful phishing and other email-related attacks. Secur-Serv’s email security services offer solutions such as security awareness training and expert consulting services to help organizations strengthen their email security posture.

Security Awareness Training

Secur-Serv’s cybersecurity awareness training provides employees with the knowledge and skills necessary to identify and avoid email phishing scams and other social engineering attacks. The training program includes:

  • Phishing simulation tool and portal: This allows organizations to simulate phishing attacks and gauge employee response, helping to identify areas where additional training is needed.
  • Online Security Education and Learning Management System: A convenient platform offering a range of courses to keep employees up to date on the latest threats and best practices.
  • Reporting and Analytics: This feature provides insights into employee performance, allowing organizations to track progress and measure the effectiveness of the training program.

End-user training courses cover topics such as:

  • Recognizing phishing and other social engineering attacks
  • Identifying potential malware behaviors
  • Reporting security threats
  • Following company IT policies and best practices
  • Adhering to data privacy and compliance regulations (e.g., GDPR, PCI DSS, HIPAA)
  • Cybersecurity Consulting

We also offer expert consulting services, provided by a designated security advisor. Organizations can use the consulting hours for:

  • Cybersecurity assessments
  • Cybersecurity policy reviews
  • Additional security education
  • Strategic security planning
  • Other cybersecurity needs

This customized approach to cybersecurity consulting is scalable to any size or type of organization, ensuring that your company receives tailored solutions for your unique needs.

The Email Security: A Comprehensive Solution

By pairing security awareness training with expert consulting services, Secur-Serv provides a holistic approach to email security. These powerful services help organizations reduce the risk of successful phishing attacks, protect their reputation by experiencing fewer breaches and secure their overall cybersecurity investment. Let us take care of your cybersecurity, so you can focus on serving your clients and growing your business.

Discover the difference with Secur-Serv by exploring our email security services today.

Learn About Our Cybersecurity Awareness Training