To help mitigate the risks of cyber threats targeting unsuspecting users every day through email, many organizations rely on Secure Email Gateways (SEG), which are designed to block incoming threats and filter out unwanted or malicious messages. 

In this article, we’ll take a closer look at some of the leading SEG solutions on the market, including their key features and benefits, to help you choose the best one for your business.


What is a Secure Email Gateway (SEG) & How Does It Work? 

Secure email gateways (SEGs) are an essential tool for email security solutions, as they provide protection against email-borne threats. However, the effectiveness of SEGs has been limited in recent years. 

Many SEGs have failed to keep up with the ever-changing threat landscape, which has led to an increase in social engineering attacks. In addition, the design of SEGs makes them less suitable for protecting cloud-based email solutions.

One limitation of SEGs is that they rely heavily on a set of predefined rules and policies, which may not be enough to detect all types of email threats. 

Sophisticated phishing attacks that use new and creative techniques can often pass through these rules and policies, which makes it difficult for SEGs to protect against them.

Another limitation is that SEGs are less effective at protecting cloud-based email solutions such as Microsoft 365 and Google Workspace. This is because the design of SEGs is based on inspecting emails inline, which means that they need to sit in line on the path of emails from the public internet to the corporate email server. 

This design makes them less effective at protecting cloud-based email solutions, which often require an API-based approach.

To overcome these limitations, organizations need to implement more advanced email security solutions. One such solution is the cloud-native email security, which uses an API-based approach to protect cloud-based email solutions. 

Cloud-native email security solutions can analyze data from multiple sources, including email, identity, and web browsing behavior, to identify threats that traditional SEGs cannot.

Another solution is to use machine learning and artificial intelligence (AI) to improve the effectiveness of SEGs. Machine learning and AI can help identify new and emerging threats that SEGs might not have seen before, allowing organizations to quickly adapt and update their security measures.

Best Secure Email Gateways in 2023

In this article, we will explore the best secure email gateways for businesses, both small and large, for the year 2023.

  1. Cisco Secure Email – It is a cloud service that filters all incoming emails to protect users against attacks like phishing, business email compromise, malware attachments, and ransomware. It complies with government and industry regulations with robust data loss prevention and encryption capabilities.

    Cisco Secure Email monitors inbound emails continuously and offers maximum flexibility to be deployed on-premises, in the cloud, virtually, or in hybrid architectures.

  1. Microsoft Defender for Office 365 – It offers native protection for Office 365, including Microsoft Outlook, and is a cloud-based email filtering service. It protects against advanced threats like BEC, phishing, and zero-day malware attacks, and collaborates with real-time reports and automatic threat mitigation responses.

    Its anti-phishing protection is powered by machine learning and advanced algorithms that can detect attempts to impersonate users or domain spoofing. Administrators can run simulations of realistic attack scenarios to identify vulnerabilities.

  1. Avanan – It uses AI to protect against sophisticated attacks, making it an ideal solution for Office 365 and Google Workspace users. It integrates well into the environment and covers multiple layers, offering threat protection inside the email inbox and monitoring incoming, outgoing, and internal emails as they are in transit.

    It can detect zero-day phishing attacks, identify BEC by flagging logins made from unusual locations, and protect against malicious attachments and URLs.

  1. SpamTitan Email Security and Protection – It is easy to set up, deploy, manage, and use and offers antivirus protection on top of spam blocking. It has features like blacklisting, whitelisting, and advanced reporting for all inbound, outbound, and internal emails.


  1. Proofpoint Email Protection – Proofpoint Email Protection is an industry-leading email security solution that uses AI to defend against BEC attacks. It can classify various types of emails accurately and stop a wide variety of email fraud, including payment redirects and supplier invoicing fraud.

    Administrators can use log data to help with troubleshooting, and Proofpoint’s AI means it offers dynamic protection that continues to evolve and defend against new malware, threats, and other malicious technology.



  2. Mimecast – Mimecast is a cloud-based secure email gateway that is ideal for larger organizations. It offers features such as defense against malware, credential harvesting, impersonation attacks, and zero-day attacks.

    The tool uses machine learning technology to protect against BEC and targeted attacks from both outside and inside the organization.



  3. Forcepoint Email Security Solution – It has Optical Character Recognition (OCR) scanning to help spot sensitive data hidden in images like scanned documents or screen grabs.

    It also has encrypted file detection to recognize custom encrypted files intended to bypass identification screening and offers advanced analysis of macros embedded in MS Office files.

    Conditional security access curbs full access to sensitive email attachments on risky mobile devices, while allowing them to be still accessible on more secure devices.