Comparison · Verified July 2026 · Every claim links to its source
ASTIS Mail vs Paubox
These two products solve different problems, and pretending otherwise would be dishonest. Paubox secures delivery. ASTIS Mail secures content. This page explains which one you actually need.
TL;DR. Paubox secures delivery: it forces TLS encryption in transit so mail lands in the recipient’s regular inbox with zero friction — no portals, no passwords — and it is deservedly loved for that (G2 4.9/5 with 543 reviews, 8,000+ US healthcare organizations, HITRUST certified). It is not end-to-end encryption and Paubox doesn’t claim it is: their own support docs describe the gateway model and the portal fallback for non-TLS recipients — linked below. ASTIS Mail secures content: sealed on your device, unreadable by ASTIS, Google, Microsoft, or anyone with server access. If your requirement is “HIPAA email for a US practice with zero workflow change,” Paubox is the stronger product. If your requirement is “the provider must be mathematically unable to read client communication” — transport encryption doesn’t reach that bar.
At a glance
The icon next to a claim opens its primary source — the vendor’s own page for their claims, our verifiable docs for ours. Security platforms shouldn’t ask to be believed.
| ASTIS Mail | Paubox | |
|---|---|---|
| Security model | ||
| Can the vendor read message content? | ||
| Can Google/Microsoft read it at rest? | No — they carry ciphertext | |
| Recipient experience | One-time key invite (browser client) | |
| Subject lines encrypted | ||
| Target market | Regulated EU business (legal, finance, health) | |
| Compliance anchors | GDPR by architecture · NIS2/DORA · SOC 2 in progress | |
| Jurisdiction | ||
| Published pricing | ||
| Reviews | No public review base yet |
Where is the trust boundary?
Every product on this market draws a line: everything left of it cannot read your content; everything right of it you have to trust. The only question that matters is where the line sits.
Keys generated and used client-side. No service can produce plaintext.
Content encrypted, but a vendor-run key server authorizes every decryption.
Encryption and access control live in the vendor’s server-side platform.
TLS in transit; content readable at rest by providers and gateways.
Paubox’s boundary is the transport layer: TLS to the recipient’s server, then normal mail. The gateway processes content by design — that’s how inbound filtering works. Paubox is transparent about this; it is a different product category, not a worse E2EE.
Where your data lives
ASTIS Mail deliberately does not host message content: decrypted mail exists only on your devices, ciphertext rides your own mailbox. Compare where each product puts plaintext.
Who holds the keys?
ASTIS Mail’s model
Body, subject, attachments, and filenames encrypted on the sender’s device; per-message key wrapped to each recipient’s public key. Providers move opaque ciphertext; ASTIS stores encrypted capsules keyed by address hashes. No message content to leak, hand over, or subpoena.
The cost of the stronger model is recipient friction: the recipient needs a key (free browser client, one-time invite). Physics, not product immaturity — end-to-end means an endpoint must exist at the other end.
Paubox’s model
Your mail server routes outbound mail through Paubox; Paubox delivers over TLS to the recipient’s server, where it arrives as a normal email. Patients and partners see nothing unusual; staff change nothing; inbound mail gets filtered — possible precisely because Paubox can process content.
What it does not do: protect content at rest. Once delivered, the message sits readable in the recipient’s mailbox, the provider’s storage, and backups. A subpoena to the provider produces plaintext. For HIPAA transit requirements with a BAA, that is a reasonable, well-executed trust decision — and it is a trust decision.
Different exams — the honest section
When transport-only is not enough
Legal privilege, trade secrets, board communication, EU personal data under GDPR/NIS2 — content that must remain confidential from infrastructure, not just in transit. “The provider and the gateway can technically read it” fails that bar by definition.
Some organizations run both: gateway hygiene for general mail, true E2EE for the subset where content confidentiality is the requirement.
When Paubox is the right answer
A US healthcare organization whose legal requirement is HIPAA: transport encryption with a BAA satisfies the Security Rule for email in transit, patients tolerate zero extra steps, inbound protection is bundled, HITRUST matters to auditors. Paubox executes this exceptionally well — its G2 rating is earned.
Known trade-offs from its own reviews: per-sender pricing that stings small practices, and recipients occasionally hesitating over whether the mail is legitimate.
Pricing
ASTIS Mail
- Solo $179/year · Team $15/seat/mo · Organization $20/seat/mo
- Self-serve, 30-day trial, no services engagement
- 25-seat firm: ≈ $4,500–6,000/year
Two honest shortlists
Pick Paubox if
- US medical practices: HIPAA checkbox with zero recipient friction
- Staff must change nothing — no plugins, no portals, no training
- Inbound security (phishing, spoofing) bundled with encryption
- HITRUST-certified vendor as an auditor requirement
Pick ASTIS Mail if
- Legal privilege and client files — provider must be unable to read them
- EU data protection: zero-knowledge channel removes the Schrems II question
- Subjects and filenames sealed, not readable in every mailbox at rest
- Threat model includes the provider itself — insider, breach, or legal process
FAQ
Is Paubox end-to-end encrypted?
No, and Paubox doesn’t claim it. It encrypts in transit (TLS) and processes mail at its gateway to enable filtering — their support docs describe the model and the portal fallback for non-TLS recipients. End-to-end means only sender and recipient devices can decrypt; that is ASTIS Mail’s model.
Is ASTIS Mail HIPAA-compliant?
ASTIS Mail’s architecture means the vendor never processes PHI in plaintext, which simplifies the BAA conversation. But ASTIS’s compliance focus is EU (GDPR, NIS2, DORA); a US practice wanting turnkey HIPAA email with zero recipient friction is better served by Paubox today.
Can I use both?
Yes, and some organizations should: Paubox-style gateway hygiene for general mail, true E2EE (ASTIS Mail) for correspondence where content confidentiality is the requirement — client files, contracts, records crossing borders.
Why is ASTIS Mail cheaper?
Different cost structures: Paubox prices per sender with gateway processing and inbound security bundled; ASTIS Mail prices per seat for an E2EE client over your existing provider. At 20 seats: roughly $3,600–4,800/yr for ASTIS Mail vs roughly $7,000–19,000/yr for Paubox (third-party-reported, July 2026).
Sources — retrieved July 2026
- Paubox Secure Message Center (gateway model, portal fallback)
- Paubox on HITRUST certification
- Paubox Email Suite pricing
- G2 Best Software Awards 2026 press release
- ASTIS security whitepaper
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Don’t trust either vendor — verify.
Read the security documentation, then run the 30-day trial on your existing Gmail or Microsoft 365 mailbox. Keep the provider. Protect the content.