Zix (OpenText) vs Proton Mail Business

How we compare:This comparison is based on official documentation, public pricing, community discussions, and aggregated user feedback, not hands-on testing by our team. We organize what real users and practitioners are saying across the web.

Zix (OpenText)

Zix, now part of OpenText, is one of the longest-established email encryption platforms with a massive install base across healthcare, finance, and government. Zix provides policy-based encryption that automatically secures emails containing sensitive data, using TLS and a secure portal fallback. Its ZixDirectory enables direct encrypted delivery between Zix customers without portal friction. Zix signs BAAs and meets HIPAA, PCI DSS, and SOX requirements.

Pros
  • Largest install base — ZixDirectory reduces portal friction
  • Mature, proven platform with 20+ years in market
  • Strong regulatory compliance (HIPAA, PCI, SOX)
  • Policy engine automates encryption decisions
  • Enterprise-grade scalability
Cons
  • Portal experience for non-Zix recipients
  • Interface feels dated compared to newer competitors
  • OpenText acquisition creates product roadmap uncertainty
  • Pricing not publicly listed

Pricing: Custom enterprise pricing

Proton Mail Business

Proton Mail Business provides zero-access end-to-end encrypted email hosted in Switzerland under some of the world's strongest privacy laws. Messages are encrypted on-device before reaching Proton's servers, meaning even Proton cannot read your email. For HIPAA-covered entities, Proton signs BAAs on its Business and Enterprise plans. The platform includes a full suite of privacy tools including Proton Calendar, Drive, and VPN.

Pros
  • Strongest privacy protections — zero-access encryption
  • Swiss jurisdiction beyond US and EU reach
  • Open source and independently audited
  • Affordable per-user pricing
  • Complete privacy suite (mail, calendar, drive, VPN)
Cons
  • Non-Proton recipients see messages via secure portal
  • Fewer enterprise admin features than competitors
  • Migration from existing email providers can be complex
  • Limited third-party integrations

Pricing: From $8.99/user/month