Healthcare email breaches remain a significant concern. In 2025, the U.S. Department of Health and Human Services (HHS) recorded 170 email-related healthcare breaches affecting over 2.5 million individuals. These events reveal ongoing gaps in email security across healthcare organizations.
Common causes of email breaches
Most email-related breaches fall into three categories:
Mailbox takeover through credential theft: Attackers use phishing to steal login credentials and take control of legitimate email accounts.
Executive and vendor impersonation: Business Email Compromise (BEC) attacks impersonate trusted executives or vendors without using malware.
Third-party email exposures: Breaches caused by unsecured email accounts belonging to vendors or business associates.
Phishing-driven mailbox takeovers accounted for about 17% of email breaches and affected over 630,000 individuals. Vendor and business associate email exposures were the most frequent type, representing 28% of recorded email incidents.
Why email security challenges persist in healthcare
Several patterns contribute to vulnerabilities in healthcare email systems:
Overreliance on user awareness: Many organizations depend on users to recognize phishing or impersonation attempts, increasing chances for human error.
Limited behavioral monitoring: Continuous tracking of email behavior to detect unusual activity is often missing.
Inconsistent technical safeguards: Encryption and identity protections vary widely, allowing protected health information (PHI) to be exposed once emails leave the sender’s control.
Identity abuse tactics: Attackers exploit trusted identities using spoofing, lookalike domains, and impersonation that can bypass standard malware filters.
Dependence on business associate agreements (BAAs): Organizations frequently rely on agreements rather than enforceable technical protections for vendors.
Impact of phishing and impersonation attacks
Phishing emails are a major vector for mailbox takeovers. These messages arrive through trusted channels, making identity abuse more difficult to detect and scalable for attackers. Impersonation of executives and vendors is increasingly common, allowing attackers to exploit trusted relationships without malware attachments or links.
Business Email Compromise (BEC) uses social engineering and identity manipulation to bypass malware detection. This method leverages familiar identities and trusted communication channels, emphasizing the need for prevention measures at the email layer.
Strategies to reduce email breach risk
A multi-layered approach is necessary to reduce email breach risks in healthcare. Efforts should focus on stopping threats early and applying technical controls consistently:
Email-layer prevention: Use tools that block phishing and impersonation before messages reach inboxes.
Targeted protection for high-risk users: Provide extra safeguards for executives, administrators, and others frequently targeted by impersonation.
Encryption at sending point: Enforce encryption controls on the sender side to protect PHI regardless of recipient email configurations.
Behavioral and identity monitoring: Implement continuous monitoring to detect suspicious sender behavior or unusual activity.
Automate threat detection: Reduce reliance on user judgment by automating phishing and identity abuse identification and response.
These strategies address gaps such as insufficient identity verification and inconsistent encryption. Proactive email-layer prevention provides a necessary foundation for reducing breach risk.
Expert insights and recent findings
Healthcare cybersecurity experts emphasize controlling PHI before it leaves the sender’s domain. Forrester noted, “Process failures and human error continue to cause data exposure.”
Many breaches could be prevented by stopping phishing and impersonation upstream, beyond relying on end-user vigilance or reactive protections.
Recommended next steps for healthcare organizations
Healthcare decision-makers can strengthen email security by:
Evaluating current phishing and impersonation defenses
Enforcing encryption policies on outbound messages
Reviewing protection for executives and other high-risk users
Implementing continuous behavioral monitoring to identify threats early
Regularly assessing third-party and vendor email security practices
For detailed guidance, read The top 3 healthcare email attacks in 2025 and how to defend against them or talk to our team at Paubox to explore reducing email breach risk in healthcare.