Healthcare Email Security in the Cloud: Risks, Challenges, and Best Practices

The digital transformation of healthcare has brought patient records, diagnostics, and even critical care management firmly into the cloud era. The sector increasingly relies on robust, scalable platforms such as Microsoft 365 and Google Workspace to facilitate communication, collaboration, and workflow continuity. Yet, a growing body of evidence paints a picture that is anything but reassuring: these technology titans, despite considerable investments in security, are falling short when it comes to protecting sensitive patient data. New research by security company Paubox, analyzing 180 email-related breaches in healthcare between January 2024 and January 2025, lays bare the systemic risks that come with entrusting protected health information (PHI) to the world’s largest cloud providers.

The Anatomy of a Healthcare Email Breach​

Email remains the primary attack vector in healthcare organizations—a fact underscored by the sheer volume and impact of incidents from the past year. Paubox’s 2025 Healthcare Email Security Report reveals an ecosystem in which both platforms’ native defenses, and the practices of their healthcare customers, have proven woefully inadequate. Misconfigurations, reliance on weak encryption standards, and the mistaken belief that cloud infrastructure alone guarantees regulatory compliance have created fertile ground for attackers. Some of the most significant findings include:

• Microsoft 365’s outsized role: Nearly 43% of reported healthcare email breaches involved Microsoft 365. This is not simply a matter of market share; it reflects challenges unique to Microsoft’s platform, such as confusing default configurations, weak enforcement of advanced email security standards, and the persistent use of legacy protocols that defeat newer safeguards.
• Encryption gaps: Despite the platforms’ claims of automatic encryption in transit, Paubox found that emails containing PHI were sometimes transmitted using deprecated TLS versions (TLS 1.0 or 1.1) in Google Workspace, while Microsoft 365 in certain deployments allowed email to be sent in plain text. These practices fall short of both industry expectations and the requirements of regulations like HIPAA and GDPR.
• Human error and misconfiguration: Most breaches were rooted in avoidable missteps. Organizations often failed to implement essential controls such as MTA-STS (Mail Transfer Agent Strict Transport Security) and had DMARC (Domain-based Message Authentication, Reporting, and Conformance) set to ‘monitor only’ rather than enforcement mode, dramatically increasing vulnerability to spoofing, interception, and phishing.

A Dangerous Perception Gap​

Perhaps most startling is the profound disconnect between perception and reality within healthcare IT leadership. Paubox’s polling data shows that 92% of surveyed IT decision-makers believed their organizations were resistant to email-related data breaches, even as 98.9% of breached organizations lacked proper baseline protections. This cultural complacency—assuming compliance simply because “the cloud is secure”—has proven to be a costly fallacy. In recent years, the Office for Civil Rights (OCR) has stepped up enforcement, handing out fines exceeding $9 million for email-related HIPAA violations, with single settlements, such as the $9.76 million penalty against Solara Medical Supplies, reinforcing the high stakes involved.

Average Cost and Regulatory Consequences​

According to IBM’s annual analysis, the average cost of a healthcare email breach soared to $9.8 million in 2024. Beyond direct financial damages, organizations face legal, reputational, and operational fallout—particularly as high-profile incidents make national headlines and government scrutiny intensifies.

Platform-by-Platform Analysis​

Microsoft 365​

Microsoft has built one of the industry’s deepest ecosystems for enterprise productivity, but this very extensibility introduces attack surfaces that can be difficult to monitor and secure.

Strengths:​

• Comprehensive Compliance Controls: Services like Microsoft Purview and Compliance Manager provide granular visibility into where sensitive data resides and how it flows within an organization.
• Integrated Threat Intelligence: Microsoft Defender for Office 365 and Sentinel import threat data from around the globe, allowing rapid response to emerging risks.
• Resilience Features: Continuous backup, version history, and ransomware recovery are in place to recover from both internal and external attacks.

Weaknesses:​

• Default security is not enough: While the toolset is powerful, Microsoft places the onus squarely on customers to configure, monitor, and audit their environments. Default settings are often designed for ease of use or broad compatibility rather than security.
• Configuration errors and legacy protocol risks: Organizations failing to disable legacy authentication protocols or enforce modern TLS can inadvertently send unencrypted data—even PHI—across networks.
• Feature sprawl and fragmentation: The swift pace of feature rollouts occasionally exceeds the hardening of security measures or the dissemination of critical information to administrators.
• Human and process risks remain dominant: Attackers find success not by breaching software, but by exploiting gaps in policy, training, and manual oversight: credential compromise and social engineering remain the root cause in most successful attacks on cloud email.

Real-World Case: Configuration Drift and Insider Risk​

Gartner and Forrester have both highlighted the continual problem of “configuration drift”—the gradual weakening of security posture as new features are activated or as environments grow more complex. Unmonitored permission escalation and Shadow IT (end users adopting unsanctioned tools or forwarding PHI to personal accounts) are frequently cited in breach analyses. Even with improved tools for DLP (Data Loss Prevention) and sensitivity labeling, policy enforcement and a culture of accountability are required to mitigate these risks.

Google Workspace​

Google’s Workspace platform touts privacy, simplicity, and out-of-the-box security. However, the Paubox report finds that these assurances often fall short in the critical context of healthcare.

Strengths:​

• Hardware-anchored security: Google’s proprietary hardware security modules, used for key management, decrease the risk of compromise from external actors.
• Immutable anti-phishing defaults: Google’s anti-phishing and authentication controls are stricter by default, protecting against many automated attacks.

Weaknesses:​

• TLS version risks: Paubox’s review discovered that Google Workspace sometimes downgrades to older, less secure versions of TLS for compatibility, quietly undermining its security claims when PHI is exchanged with legacy systems.
• Customer responsibility: Google, like Microsoft, expects customers to not only configure security features but actively monitor and test email traffic for compliance.
• Opaque administrative complexity: Google’s admin console, while streamlined, often hides advanced email routing and encryption settings, leaving some organizations unaware of insecure data flows.

Unique Issues in Healthcare Use​

One overlooked risk is the expectation of seamless interoperability with external parties—labs, referral networks, insurance companies—often using older or patched-together systems. Google’s willingness to "fall back" to legacy encryption (or no encryption at all) can expose the weakest link in even well-intentioned compliance workflows.

The Broader Healthcare Landscape: Risks Beyond the Cloud​

While platform missteps dominate headlines, the healthcare industry faces a much broader set of structural risks. The rapid integration of IoT devices, legacy clinical applications, and overworked staff all contribute to the spiraling attack surface, amplifying the likelihood of data being exposed—sometimes without malicious intent.

• Delayed patching and legacy technologies: Many healthcare organizations rely on aging imaging software or interconnected endpoints that may simply be incapable of enforcing modern cryptographic standards or receiving timely security patches.
• Hybrid environments: The confluence of on-premises infrastructure, third-party application integrations, and mobile endpoints means a single misconfiguration or missing patch can become a vector for far-reaching breaches.

Consequences: From PHI Leaks to Ransomware​

The fallout from cloud email insecurity is neither theoretical nor marginal. Ransomware attacks against healthcare surged 264% since 2018, with the majority originating from phishing emails. Attackers exploit gaps in platform security and configuration to snatch login credentials, plant malicious payloads, or silently harvest confidential data. In the most devastating scenarios, attackers encrypt hospital networks or exfiltrate records, demanding multi-million dollar payments to avoid patient exposure or regulatory reprisal.
Organizations slow to apply security patches, or those that fail to review access logs and DLP alerts, are especially vulnerable, often becoming repeat victims. The aggregate cost is staggering, with patient trust and even clinical outcomes at risk when systems are taken offline.

Why Default Configurations Are Not Enough​

Paubox’s central conclusion is stark: relying on cloud providers’ standard configurations is insufficient to satisfy legal, ethical, and operational obligations in healthcare. Both Microsoft and Google make it clear—often in the fine print—that the customer is responsible for correct implementation and monitoring. This creates a dangerous knowledge gap where overworked IT staff assume compliance has been handled, when in fact critical functions like TLS enforcement, logging, or phishing protection may be incomplete or entirely disabled.
A CISA (Cybersecurity and Infrastructure Security Agency) directive for federal cloud environments, while primarily targeted at government, has wider lessons: all organizations should regularly audit their Microsoft 365 or Google Workspace tenants, enforce multi-factor authentication, restrict third-party app access, and strictly monitor for risky configurations. CISA even released an automated tool—ScubaGear—to make auditing easier for organizations both inside and outside government.

Best Practices and Paubox Recommendations​

To mitigate these serious risks, Paubox and security analysts point to several practical steps:

• Mandatory End-to-End Encryption: Do not rely solely on TLS for email; invest in proven end-to-end encryption services, especially when handling PHI or other regulated data.
• Guard Against Legacy Protocols: Regularly audit and disable legacy access and mail protocols that allow weak or no encryption. Ensure all endpoints are using current, secure versions of TLS (1.2 or later).
• Apply Strict Email Authentication Policies: Move DMARC from ‘monitor only’ to ‘enforcement’ and implement MTA-STS to guarantee transmission security.
• Continuous Monitoring and Testing: Regularly test email systems for configuration drift, phishing exposure, and compliance with HIPAA/GPDR, using both automated tools and third-party audits.
• Security Awareness Training: End-user behaviors—phishing susceptibility, credential leakage, or negligence—are implicated in most modern breaches. Periodic staff training and simulated phishing attacks can reduce risk.

The Legal and Compliance Landscape​

The momentum for stronger enforcement is gathering. Regulators are increasingly intolerant of “blind trust” in the cloud, demanding proactive risk evaluation and evidence of functional, tested controls. Recent OCR enforcement actions—levying some of the largest fines ever for PHI exposure—serve as poignant reminders that accountability for data breaches rests ultimately with the custodian, not the vendor.

Critical Analysis: Strengths and Unresolved Risks​

What the Platforms Do Right​

Both Microsoft 365 and Google Workspace offer unmatched scalability, robust compliance toolkits, and—when properly configured—the technical means to support secure healthcare operations. Their ongoing push toward AI-driven automation, threat detection, and intuitive interfaces helps level the playing field for resource-constrained healthcare IT teams.

Where They Fall Short​

Crucially, both platforms put far too much responsibility on customers for correct configuration—a practice that fails to account for real-world resource shortages, skill gaps, and the sector’s reliance on legacy systems. Encryption defaults may lull administrators into a false sense of security, while opt-in advanced features often require deep technical expertise to deploy and manage. In environments where lives are on the line and margins for error are slim, these weaknesses demand urgent attention.
Platforms also struggle to strike a balance between ease of use and least privilege. Self-service features, broad third-party app ecosystems, and permissive sharing defaults invite errors, while attackers exploit these features with increasingly sophisticated tactics.

Unverifiable or Cautionary Claims​

It is worth noting that direct evidence tying specific Google Workspace deployments to real-world PHI compromise via legacy TLS use is limited. While the downgrade to TLS 1.0/1.1 is documented as a compatibility risk, public disclosure of active exploitation remains infrequent, possibly due to underreporting or regulatory opacity. Readers should interpret this caveat with due caution, while recognizing the clear technical consensus regarding the insecurity of these protocols.

Lessons for a Digital Healthcare Future​

The digital revolution in healthcare will only further accelerate. As more patient interactions, diagnostics, and treatment plans reside in the cloud, it is essential for organizations—regardless of size—to view email security not as a static compliance burden but as a living, evolving challenge. The ability to audit, adapt, and improve security postures must be woven into the everyday fabric of healthcare IT operations.
For healthcare leaders, security officers, and clinicians alike, the time to act decisively is now. Abandon assumptions that “the cloud is secure by default”; demand transparency from vendors, prioritize investment in training and audit tooling, and treat every misconfiguration or incident as both a lesson and an opportunity to improve.
Only by embracing these realities can healthcare organizations hope to safeguard not just data, but trust—the fundamental currency of care in an age where the boundaries between technology and medicine are vanishingly thin.

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Source: Techzine Global Microsoft and Google fail to protect patient data