Secure email gateways (SEGs) provide more advanced protection, including threat detection, data loss prevention (DLP), encryption, and email continuity. They are generally suited to organizations with more complex security needs. On the other hand, traditional email filters provide basic spam and malware filtering, are cost-effective and simpler to manage, suitable for smaller organizations with less sophisticated security requirements.

 

Importance of email security

Email remains a central communication tool for organizations, but it can also provide cybercriminals with a route into systems and sensitive information. Microsoft notes that email-based threats can include phishing, malware, business email compromise, spoofing, and data loss.

A strong email security strategy can help organizations identify and block malicious messages before they reach users, while reducing the risk of sensitive information being exposed. Microsoft recommends using layered protections such as email filtering, authentication protocols including SPF, DKIM, and DMARC, encryption, data loss prevention (DLP), multifactor authentication (MFA), threat detection, and security awareness training.

Email security is particularly important because attackers can exploit both technical vulnerabilities and human error. A convincing phishing email, for example, may trick an employee into clicking a malicious link, revealing credentials or sharing sensitive information. Combining technical controls with employee training can therefore help organizations reduce the likelihood and potential impact of email-based attacks.

An SEG and a traditional email filter both aim to protect users from malicious and unwanted emails, but they do so in different ways and with varying levels of sophistication.

See also: HIPAA Compliant Email: The Definitive Guide

 

Secure email gateway

Secure email gateways (SEGs) add a layer of protection between an organization's email environment and potentially harmful messages from outside the network. Gaboret’s study, The successful low-cost deployment of a secure email gateway, describes an SEG as a security tool that can scan incoming and outgoing email for threats before messages reach their intended recipients.

An SEG can use content filtering to identify and block suspicious messages based on factors such as keywords, URLs, attachments, and other characteristics. The study indicates several functions that can be incorporated into an email gateway, including:

  • Spam and malware filtering to remove unwanted or malicious messages.
  • DNS authentication to help detect spoofed or fraudulent senders.
  • Impersonation protection to identify attempts to mimic legitimate users or organizations.
  • Malicious URL detection to prevent users from accessing harmful links.
  • Attachment scanning to identify potentially malicious code within files.
  • Outbound email scanning to help prevent sensitive information from leaving the organization.

The gateway can also quarantine messages that trigger security checks, allowing them to be reviewed before they are delivered to the recipient. Gaboret’s research highlights the value of this approach as part of a broader, layered email security strategy rather than relying on users to identify every threat themselves.

SEGs can also support email encryption, helping protect the confidentiality of messages while they are being transmitted or stored. However, the study notes that an SEG should not be treated as a standalone security solution. Organizations still need complementary measures such as security awareness training and other technical controls to address threats that may bypass gateway protection.

 

Traditional email filter

Traditional email filters help organizations identify and manage unwanted emails before they reach users’ inboxes. The study Comparison of Deep and Traditional Learning Methods for Email Spam Filtering describes traditional machine learning-based approaches that analyze characteristics of email messages to determine whether they are spam or legitimate. Source study

Traditional email filters can protect users by:

  • Detecting spam: Filters analyze email characteristics to identify messages that resemble known spam.
  • Examining email content: They can assess words, phrases, and other features within a message to help classify it.
  • Filtering unwanted messages: Emails identified as spam can be blocked, rejected, or moved to a spam folder instead of reaching the main inbox.
  • Automating email classification: Traditional filtering methods use established classification techniques to process large numbers of messages without requiring users to manually assess each email.
  • Reducing exposure to unwanted emails: By removing suspected spam before delivery, filters can reduce the number of potentially unwanted or suspicious messages users encounter.

Traditional email filtering therefore provides a basic layer of protection by separating likely spam from legitimate correspondence and reducing the amount of unwanted email that reaches users.

 

FAQS

What role does data loss prevention (DLP) play in email security?

Data loss prevention (DLP) helps prevent the accidental or intentional sharing of sensitive information via email. DLP systems monitor outgoing emails for confidential content and can block or encrypt the email if it violates security policies.

 

How often should I update my email security settings?

You should regularly review and update your email security settings, especially after any security incidents, software updates, or changes in your usage patterns. At a minimum, review settings every few months to ensure they align with current security best practices and threats.