Paubox

Paubox sells encrypted email built specifically for healthcare’s compliance requirements. Its core pitch is that HIPAA-compliant encryption shouldn’t require the recipient to log into a separate portal to read a message: Paubox encrypts outbound email in transit and at rest automatically, so protected health information (PHI) moves through standard email clients without extra steps for either sender or recipient. The company has extended that same automatic-encryption model into inbound filtering and phishing/malware protection under its Paubox Email Suite.

Founded in 2014 by Hoala Greevy and headquartered in San Francisco, Paubox raised a $4 million Series A led by Arthur Ventures and has since brought total funding to roughly $14.2 million. By 2024 the company reported around $10 million in annual revenue and roughly 1,200 customers, up from about $1.2 million in revenue in 2018, reflecting steady if unspectacular growth in a healthcare IT market that is slow-moving but sticky once a vendor is embedded in clinical workflows.

Paubox competes in a category with entrenched incumbents (Virtru, Zix/OpenText, Microsoft’s own encryption tooling) but has built a specific reputation around removing user friction, which matters in healthcare settings where clinical staff have little patience for extra authentication steps. Its growth has been steady rather than explosive, consistent with a mature niche product rather than a fast-disrupting one.