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Karan Singh Karan is a highly experienced DevOps Engineer with over 13 years of experience in the IT industry. Throughout his career, he has developed a deep understanding of the principles of DevOps, including continuous integration and deployment, automated testing, and infrastructure as code.

Building an Email Security Stack for the Enterprise: A Comprehensive Guide

3 min read

Email. For better or worse, it’s the backbone of business communication. While you can’t argue against its convenience and cost-effectiveness, it is also one of the single biggest cybersecurity vulnerabilities that enterprises face today. With phishing, social engineering, and business email compromise (BEC) attacks growing more sophisticated each year, no organization can afford to leave email exposed – especially as regulations continue to tighten up around user data security and privacy. 

So, how do you lock down the email threat surface for an enterprise? By building a layered email security stack covering all the gaps, not just what a gateway scanner can catch. This goes beyond traditional tools to also cover endpoints, user training, and having an incident response plan in place.

The First Line of Defense: Email Gateways

Naturally, the email gateways themselves form the first line of defense when it comes to email security. And while legacy gateways served their purpose in protecting inboxes, today’s advanced threats require a bit more of a sophisticated approach:

  • Multi-layered threat detection – Modern gateways should go beyond basic spam and malware filtering to detect weaponized content like malicious links, documents, and impersonation attacks. This requires deep content analysis, sandboxing of attachments, and utilization of threat intelligence.
  • Adaptive authentication – Gateways can analyze contextual signals and apply adaptive authentication measures like multi-factor authentication when suspicious activity is detected. This verifies the identity of users before allowing access.
  • Automated remediation – Dangerous messages and threats should be automatically quarantined or deleted pre and post-delivery to contain attacks before they spread.

The top email security vendors today bake these advanced protections into their solutions. They combine powerful upfront threat analysis with background threat containment to create a tightly integrated defense. And while no solution can claim to block 100% of threats, modern gateways employing multilayered analysis, verification, and remediation provide the most robust frontline email defense available.

Closing Endpoints and Inboxes

With strong gateways in place, we’ve got some solid first-line defense. But as you know, determined hackers are crafty and some attacks inevitably get through. That’s why securing endpoints and locking down inboxes is critical for the next layer of protection. We need to implement defense-in-depth.

For endpoints, running advanced email security suites allows real-time scanning of links and attachments not just in emails, but also Office documents and PDFs where threats love to hide.

But we can’t just rely on reactive scanning alone nowadays. The goal should be to continuously analyze user activity across applications and actively hunt for advanced threats. Plus, tight permission controls and access restrictions depending on roles and risk to limit damage from threats.

For inboxes, encrypting user mailboxes is a quick win to restrict unauthorized access. Classification tools help identify sensitive emails and automatically apply encryption, limit sharing/downloads, and block potential data leaks through forwards or copies.

Together, these kinds of inbox and endpoint controls contain advanced attacks that slip past gateways before they spread across digital estate like wildfire. They buy precious time to respond appropriately.

The Human Firewall: Training Users

No matter how advanced your security tools get, humans remain the weak link that hackers look to exploit. That’s why employees are prime targets for spear phishing and social engineering. While you can put guardrails in place and hope they are sufficient, the best way to overcome this is to roll out comprehensive security training for all employees – especially those who have access to sensitive data or high value systems. These training programs should cover the following (at a minimum):

  • Identifying Suspicious Emails: Train staff on common red flags like malicious links, spoofed domains, compromised accounts. Share recent real world examples of threats received internally so they relate.
  • Safe Email Hygiene: Share best practices for safer email handling like avoiding direct clicks, using hover previews for URLs, opening attachments in sandboxes first before local access.
  • Incident Reporting: Establish clear protocols for staff if they suspect an email is malicious – who to alert, steps to isolate the threat without spreading it by forwarding or sharing access inappropriately. Reward reporting.

It also helps to implement continuous reinforcement through simulated phishing and business email compromise campaigns, mock tests, and so on. The goal is evaluations and improvement, not punishments for getting things wrong. You want employees as allies in your security, not obstacles. 

Streamlined Incident Response

When a threat does slip through the cracks, The impact of a breach often comes down to how quickly you can respond. This is where automatic playbooks and workflows can be invaluable to contain threats faster. If a suspicious email evades detection and tricks a user, when flagged we need to act instantly:

  • Suspend user access immediately until verification, to limit damage.
  • Terminate sessions across all devices and apps the user is logged into, to kick them out.
  • Isolate connected systems, limit external sharing, or even disable email organization-wide depending on breach severity until the threat is neutralized.
  • Notify affected users, security teams automatically on a need-to-know basis.

The key is having workflows that allow security personnel, IT teams, and employees to coordinate seamlessly. Ideally, you want quick, consistent, and contained responses every single time. This takes pressure off security teams while drastically reducing risk.

Final Word

Sophisticated threats require sophisticated, multilayered protection when it comes to enterprise email security today. Legacy gateways and perimeter tools are no longer enough.

With advanced gateways, endpoint, and inbox controls, security-aware employees, and automated response workflows, companies can stay multiple steps ahead of attackers. Will it prevent every single breach attempt? Probably not. But it will deter the vast majority from ever impacting your business.

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Karan Singh Karan is a highly experienced DevOps Engineer with over 13 years of experience in the IT industry. Throughout his career, he has developed a deep understanding of the principles of DevOps, including continuous integration and deployment, automated testing, and infrastructure as code.
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