Email security should be a top priority for your organization. Email remains the number one vector used by cyber-criminals to target your corporate data, and email-based attacks such as phishing, business email compromise, and spam are constantly on the rise. Your organization’s first line of defence against these attacks should be an email security solution; this can defend your users against spam, phishing, malware, and viruses.
Secure email gateways (SEGs) are a category of email security tools that filter emails as they enter or leave your email server. Emails are routed through the gateway service, and so typically require your MX-records to be changed, regardless of email platform. Many email providers today also offer a cloud-native email security option, known as “Integrated Cloud Email Security” (ICES), either alongside or as a replacement for the traditional SEG. These solutions scan emails for content that may indicate phishing, account compromise, or malicious downloads. These can integrate directly with cloud email platforms such as M365 and Google Workspace.
There are many email security gateway solutions available. To help you find the right solution, we’ve put together our list of the top email security solutions, covering both secure email gateways, ICES, and cloud-native email security options. In each listing, we’ll cover key features, spam filtering effectiveness, deployment, ease-of-use, our internal technical testing, and wider market positioning to give an informed suggestion regarding the ideal use case for each platform.
Email Security: Everything You Need To Know (FAQs)
What Is A Secure Email Gateway?
A secure email gateway (SEG) is an email security tool that prevents malicious emails from being delivered or sent from your email network. SEGs filter email messages using signature analysis, attachment sandboxing, URL scanning, and machine learning in conjunction with configured admin policies, to remove harmful email content before it reaches corporate mail servers and user inboxes. Suspicious content is either quarantined, deleted, or marked as unsafe.
Secure email gateways are typically cloud-based but can be deployed as an on-premises or hybrid appliance. They are usually deployed through redirecting your DNS MX-records, which directs email messages via the filtering service before they reach user inboxes.
What Are Integrated Cloud Email Security Solutions?
Integrated Cloud Email Security (ICES) Solutions are cloud-native email security tools that can be used alongside (or to replace) a secure email gateway. Unlike SEGs that require you to redirect DNS MX-records, these tools are cloud-native, and can integrate directly into cloud email platforms such as Microsoft 365 and Google Workspace via API.
Not only does this approach have a faster deployment, but it also results in more effective protection against threats inside the email inbox. ICES solutions will use machine learning to scan internal email communications and identify indicators-of-compromise (IOCs), signifying an account has been compromised to send out malicious email messages. Using these tools, suspicious emails can be automatically removed from all user’s inboxes, even after delivery.
Our recommendation is that businesses needing strong email security should consider implementing multi-layered email protection, pairing a gateway with some form of cloud-native inbox-based email security solution.
Why Is Enterprise Email Security Important?
Email continues to be the top threat vector for many times of cyber-crime. 81% of organizations around the world have seen an increase in phishing since 2020, and in 2021 almost 40% of data breaches involved a phishing attack.
Originally, spam was the biggest nuisance that companies faced with email. Ranging from the farcical (far-off Royals promising riches) to the malicious (adult and harmful content sent to mailboxes). Spam was a major headache for IT admins in the early days of the internet and continues to be a problem even now – estimates are that up to 49% of all emails are spam.
SEGs can deal with spam content very effectively – they often use new or low-reputation domains which can be quickly blocked by the email filter. But modern email threats are much more targeted and advanced. Phishing is one of the most common causes of data breach today. They often originate within the email channel and aim to trick users into clicking harmful web links or making fraudulent payments. Advanced malware and ransomware also commonly spread via phishing messages or by compromised email accounts.
Modern email security tools, such as SEGs and Integrated Cloud Email Security solutions, protect against these threats. They use a range of techniques, including attachment sandboxing, URL filtering, domain reputation assessment, and machine learning, to filter email content.
It is important for all organizations to have an effective email security framework in place to protect users, customers, and partners from sophisticated email threats such as spam, malware, phishing, and business email compromise. Email security is also important to ensure and demonstrate compliance with data security regulations.
What Are The Key Features Of Secure Email Gateways?
Email security gateways are designed to act as a shield for your email network, blocking inbound malicious email content from reaching user inboxes, and preventing outbound malicious email content from being delivered. Admins should have the ability to configure policies which govern how this filtering works. They may wish to block emails from certain domains or allow emails from known safe senders.
In addition, email security gateways should provide detailed reporting to help organizations track incoming email threats. Many email gateways also include integrated, complementary email technologies, such as email archiving, encryption and DMARC.
Key features of secure email gateways include:
- Protection against harmful email content across all email platforms (M365, Google Workspace, Exchange On-prem etc)
- Admin policies and controls to govern how the email filter works
- URL filtering
- Attachment sandboxing
- Integrated email security tools, e.g. email archive, email encryption, DMARC
How Do Email Security Tools Work?
Email security tools are designed to protect email accounts, content, attachments, and users against malicious activity, compromise, or breach. This covers a broad range of use cases, including preventing the delivery or sending of malicious email content, such as harmful attachments, ransomware, and phishing mail.
The tools are also responsible for encrypting email messages that contain sensitive data, preventing users from clicking on malicious URLs, providing data leakage protection (DLP), and displaying warning banners on potentially harmful email messages.
How Does A Secure Email Gateway Work?
Before cloud email hosting, the most common form of email security tool was the “secure email gateway (SEG)”, a physical appliance that would sit in front of the email network and monitor incoming and outbound email traffic to remove spam and malware. Today, email security tools are more commonly cloud-based, with organizations redirecting their mail exchange (MX records) to point their email towards a cloud-based SEG.
Many email security gateways use a mixture of email content scanning, domain reputation, URL scanning, and attachment sandboxing to make a deterministic assessment of an incoming email message. If the message is deemed malicious, it is blocked; if it is deemed safe, it is delivered.
These tools work using a variety of techniques including greylisting, real time blacklists (RBL’s), constantly updated spam definitions, pre-defined DLP rules, anti-malware, and sandboxing engines to detect and remediate against malicious email content.
In the era of cloud-based email platforms, such as Microsoft 365 and Google Workspace, a new category of SaaS-based email security tools has emerged. These services, named “integrated cloud email security” (ICES) solutions by Gartner, address cloud-based vulnerabilities, most sophisticated phishing threats that evade the traditional, static controls used by SEG services.
These tools integrate directly into the inbox environment and are deployed either via an API connection or using mail flow rules. These tools can address SEG gaps by scanning the inbox environment directly. This means they can scan internal email which SEG’s traditional have been unable to achieve. They are also able to remove potentially malicious email content from all mailboxes, instantly – even after an email has been delivered.