Why healthcare organizations should replace their legacy SEG

Email is the most common communication in the healthcare industry; however, it’s also the most exploited vector for cyberattackers seeking access to electronic protected health information (ePHI), financial data, and operational systems. According to Paubox, 180 healthcare organizations reported email-related security breaches to the HHS Office for Civil Rights (OCR) between January 1, 2024, and January 31, 2025. The growing trend highlights how traditional secure email gateways (SEGs) are no longer sufficient to defend against modern threats like phishing, business email compromise (BEC), and ransomware.

Legacy SEGs were designed for a different era, when most attacks relied on malicious attachments or known malware signatures. Today’s cybercriminals use advanced social engineering, AI-generated messages, and time-delayed URLs that easily bypass perimeter-based filtering. As healthcare continues its digital transformation, relying on outdated SEG technology creates blind spots that put patient data, compliance, and trust at risk.

To stay ahead, healthcare organizations must replace legacy SEGs with modern, AI-driven, cloud-native solutions that detect anomalies, analyze behavioral patterns, and integrate seamlessly with platforms like Microsoft 365 and Google Workspace. Doing so strengthens protection against evolving threats, supports HIPAA compliance, ensures business continuity, and upholds the confidentiality that patients expect from their providers.

Why traditional SEGs can’t keep up with modern email threats

Healthcare is under attack

Healthcare organizations are increasingly targeted. As of the 18th of October, 2025, the U.S. Department of Health and Human Services’s Office for Civil Rights (OCR) breach report portal received over 400 breach reports in the healthcare sector. Moreover, phishing and email-based threats dominate: more than 90% of all cyberattacks starting with a phishing email. According to Paubox, phishing is the leading cause of healthcare breaches, accounting for over 70% of data breaches as of 2024.

These statistics indicate that email is no longer just an administrative tool; it’s now the main target for attacks.

Legacy SEGs are falling behind

Legacy SEGs were designed for spam and basic phishing, not the sophisticated social engineering and BEC attacks dominating today’s inboxes. With more than 90% of cyberattacks starting with an email, and many SEGs still relying on static rules and blocklists, attackers can easily bypass these.

In healthcare, where a single breached inbox can expose thousands of patient records and trigger HIPAA penalties, this outdated model is risky. SEGs struggle to detect well-crafted impersonation and thread hijacking attempts that mimic trusted senders.

Modern, AI-powered email security uses behavioral analysis to learn communication patterns and flag anomalies in real time, something legacy SEGs were never built to do.

Healthcare’s legacy systems amplify the risk

Healthcare organizations often run legacy infrastructures with constrained budgets, complex vendor ecosystems, and regulatory burdens. The study Digital transformation of healthcare sector: What is impeding adoption and continued usage of technology-driven innovations by end-users?, notes that legacy systems create numerous obstacles to healthcare efficiency, which can compromise patient safety, delay treatments, and contribute to provider burnout.

Healthcare’s reliance on outdated email gateways only adds to these challenges. Legacy SEGs often can’t integrate seamlessly with modern cloud platforms or evolving security tools, leaving critical communication channels exposed. As a result, cybercriminals exploit these weak points to gain access to networks, steal patient data, and disrupt care delivery.

Why replacing the SEG should be a strategic priority

Protecting patient ePHI and compliance

Healthcare organizations carry the burden of protecting ePHI under regulations like HIPAA in the U.S. or similar frameworks elsewhere. Email is a major channel of data transfer.

Replacing an inadequate SEG with a solution that integrates encryption, data-loss prevention (DLP), multi-factor authentication (MFA), and behavior-based detection is a compliance and patient-trust imperative.

Reducing operational risk and downtime

When a breach or ransomware event hits a hospital or clinic, the consequences go beyond data theft; patient care and business operations can be impacted. The CSC 2.0 Healthcare Cybersecurity Needs a Check Up report describes how ransomware attacks have disrupted care delivery, equipment, and services.

An SEG that fails to catch a sophisticated email attack may allow lateral movement, credential compromise, or malicious attachments, leading to broader system compromise. Upgrading the email gateway architecture thus becomes an element of business continuity and patient safety, not just IT.

Related: Why 83% of healthcare IT teams say legacy systems disrupt operations

Aligning with the modern security stack

Newer frameworks such as zero trust and secure access service edge (SASE) expect email security to operate across identity, endpoint, cloud, and network contexts. A traditional SEG often sits only at the email perimeter and may not integrate with identity or real-time behavioral analytics.

For healthcare organizations moving toward cloud-native, hybrid, or digital-first models, sticking with a legacy SEG can become an impediment to architectural agility and security posture.

Addressing ever-increasing vendor and third-party complexity

Healthcare doesn’t operate in isolation. Laboratories, imaging centers, supply chain vendors, billing partners, and referral networks mean circular email flows and third-party risk. According to the 2025 Verizon DBIR, third-party involvement in breaches has doubled from 15% to almost 30%.

If the SEG cannot effectively inspect or manage emails from or to third parties (including cloud services), the organization’s risk surface expands significantly. A replacement SEG can support more granular control, identity-based filtering, vendor-centric policy enforcement, and retrospective remediation.

Common signs the SEG needs replacing

Here are some signs to recognize when your SEG is failing:

• Increasing successful phishing/BEC incidents: If your security team logs rising numbers of successful phishing attacks, impersonation emails, or account-takeover events despite having an SEG in place, that’s a red flag. Since many modern attacks bypass payload-based filters, this suggests a gateway that can’t handle zero-day or behavioral threats.
• Legacy architecture not supporting cloud email: Many healthcare organizations have adopted cloud email platforms, such as Microsoft 365 and Google Workspace, but still route through on-premises appliances, causing latency, complexity, and limited visibility. Cloud-native or API-based email security may be required.
• Compliance audits flag email controls as weak: If internal or external audits reveal that your email system is still using unsupported encryption, lacks automation for DLP, or fails to integrate log data into your SIEM/KDR, the SEG may be outdated.
• Slow incident response and manual remediation: If your email security team is manually hunting threats, relying on user-reported phishing rather than automatic remediation, or dealing with lengthy clean-up after an email compromise, your gateway may be underperforming.
• Business requirements outpacing the gateway: Healthcare environments change fast: telehealth, mobile workflows, partner ecosystems, device-to-email, and IoMT (Internet of Medical Things) integration. If your SEG cannot adapt, cannot inspect mobile attachments, cannot handle encryption of PHI in cloud flows, and cannot integrate with identity or SIEM, then the gateway is a bottleneck and a liability.

What a replacement SEG should provide

Replacing a legacy SEG isn’t simply buying a newer version of the same appliance. It requires a modern email security platform that matches healthcare’s complexity. Key capabilities include:

• Behavioral and identity-based threat detection: Modern gateways must analyze sender behavior, recipient patterns, user context, and anomaly detection, not just signature and attachment scanning. For example, detecting when an executive suddenly requests large fund transfers or when a vendor mailbox starts sending large attachments externally.
• Real-time post-delivery remediation: Threats often land in the inbox before they’re flagged. A modern gateway should retract or quarantine suspicious messages or remove malicious links post-delivery.
• Seamless encryption and DLP for ePHI: Because email in healthcare often involves PHI, the gateway needs to automatically encrypt based on policy, detect sensitive content (e.g., patient identifiers, diagnoses, financial data) and manage outbound flows to ensure no unauthorized data leaves the network.
• Third-party email risk management: The gateway must handle inbound/outbound email from known addresses, from lab partners, device vendors, imaging outsiders, and supply-chain contractors. It must support segmentation, partner-specific policies, and retrospective visibility of third-party access. The doubling of third-party involvement in breaches emphasises this.
• Integration with broader security stack and cloud: The email gateway should integrate with identity providers, endpoint detection & response (EDR), security information/event management (SIEM), Secure Web Gateway (SWG), and SASE frameworks. In healthcare, this allows email threats to be correlated with endpoint mis-behaviour, device users, and network anomalies.
• Scalability and cloud-native deployment: Healthcare organizations often span multiple geographical locations, cloud services, mobile devices, and devices-of-things (IoMT). The gateway solution must be cloud-native or hybrid, support rapid scaling, offer high availability, and be easy to manage across regional compliance regimes.
• Reporting, audit, and compliance-ready logs: The gateway should supply robust logging, incident reviews, audit trails for regulatory compliance, and metrics for KPIs.

Replacing your SEG with Paubox

For healthcare organizations, inbound emails are one of the biggest entry points for cyberattacks, including phishing, spoofing, ransomware, and business email compromise (BEC). Paubox Inbound Email Security provides advanced, healthcare-focused protection that legacy SEGs often miss.

Using AI-driven behavioral analysis and intent monitoring, Paubox scans incoming messages for subtle signs of malicious activity. It detects anomalies in communication patterns, flags suspicious senders, and blocks attacks before they reach user inboxes, protecting both staff and patient data.

Key benefits for healthcare organizations include:

• Advanced threat detection that adapts to evolving cyber tactics.
• Reduced operational overhead, eliminating the need for complex appliances or a manual triage process.
• Seamless user experience, with threats blocked automatically without disrupting daily email workflows.
• Enhanced compliance, supporting HIPAA and BAAs by preventing malicious inbound messages from compromising ePHI.

By focusing on inbound threat protection, Paubox helps healthcare organizations close critical security gaps left by legacy SEGs, ensuring sensitive data remains safe while streamlining email management.

See also: HIPAA Compliant Email: The Definitive Guide (2025 Update)

FAQS

Do employees need special training to use modern email security tools?

Most modern solutions are designed to be seamless for users. For example, AI-powered inbound security and automatic encryption often work behind the scenes without requiring extra steps from staff.

Can modern email security solutions help with HIPAA compliance?

Yes. Advanced email security platforms often include encryption, secure inbound threat detection, and business associate agreements (BAAs), helping organizations meet HIPAA and other regulatory requirements.

How does Paubox differ from traditional SEGs?

Paubox is cloud-native and healthcare-focused. It provides automatic encryption for outbound emails and AI-driven inbound threat protection without portals or extra logins, unlike many legacy SEGs.