Beyond Encryption Mailock for M365 vs Kiteworks Secure Email: Side-by-Side Comparison (2026)

Beyond Encryption Mailock for M365

SMB and mid-market teams standardized on Microsoft 365 should pick Beyond Encryption Mailock for M365 if message revocation is non-negotiable; the ability to recall emails even after a recipient opens them covers the mistake you'll inevitably make sending sensitive data to the wrong person. AES-256 encryption with SMS and Q&A recipient verification handles NIST PR.AA without requiring users to manage separate identity infrastructure. Skip this if your organization needs DLP that catches data before it leaves the network or if you're already enforcing encryption at the gateway level; Mailock layers on top of M365 rather than replacing email security controls.

Kiteworks Secure Email

Mid-market and enterprise teams handling regulated data through email will find Kiteworks Secure Email worth the deployment effort because its policy automation engine actually enforces DLP rules at send-time rather than just logging violations afterward. FIPS 140-2 validated encryption across S/MIME, OpenPGP, and TLS 1.3 plus sandboxing and content disarm coverage address the PR.DS and PR.PS controls that compliance auditors actually ask about. Skip this if your organization needs a lightweight, user-friction-free solution; Kiteworks requires integration work and will surface policy violations that force conversations with business teams about what email traffic is actually allowed.