Mailvelope

PGP encryption for Gmail, Outlook.com, and Yahoo — without switching email providers.

Open source

Adequate

https://mailvelope.com · Reviewed 2026-04-02 · Editorial assessment by Mike Schneider — based on public security research and audits

What should journalists know about Mailvelope?

Mailvelope solves the biggest PGP adoption problem: nobody wants to switch email providers. It bolts OpenPGP encryption onto Gmail, Outlook.com, and Yahoo webmail as a browser extension. Open-source since 2012, audited ten times by firms including Cure53, SEC Consult, and 0xche. The German BSI funded its development in 2018 to add encrypted web forms and GnuPG integration. Private keys never leave your browser. The tradeoff: you're trusting a browser extension with your encryption, which has a larger attack surface than a standalone app. And PGP email itself is losing ground to Signal and other modern E2EE protocols — most security researchers now recommend against PGP for routine secure communication. Mailvelope is still the best option when PGP email is a hard requirement, but in 2026, that requirement is increasingly rare.

Best for

Adding PGP encryption to existing webmail accounts. Receiving encrypted tips from sources who already use PGP. Newsrooms standardizing on Gmail or Microsoft 365 that need encryption for specific threads. Compliance workflows requiring OpenPGP.

Not for

Journalists facing state-level adversaries (use Tails + Thunderbird for air-gapped PGP). Mobile email — Mailvelope only works in desktop browsers. Routine secure messaging — Signal is simpler and safer for most journalist-source communication.

Security & Privacy

Encryption in transit Yes

Data is scrambled while being sent to their servers

Encryption at rest Yes

Data is scrambled when stored on their servers

Data jurisdiction Local — private keys stored in browser extension, never on Mailvelope servers. Optional Mailvelope Key Server for public key distribution is hosted in Germany.

Where servers are located — affects which governments can request your data

Security rating Adequate

Encryption runs locally in the browser. The extension does not transmit email content or private keys to Mailvelope servers. The Web Key Directory (WKD) lookup feature makes HTTP requests to the sender's domain by default, which can expose user activity — disable in settings if this matters. If you use the Mailvelope Key Server, your public key and email address are stored on German servers. No analytics or tracking in the extension.

How to protect yourself:

Verify recipient public keys through a second channel before sending sensitive material. Use a strong passphrase for your private key. Keep the extension updated — the 2025 audit found a clickjacking vulnerability patched in v6.1.0. Back up your private key securely outside the browser. Disable automatic WKD lookups in settings to prevent information leakage to sender domains. Consider whether Signal or SecureDrop would serve your use case better than PGP email.

Open-source, ten independent audits since 2013, BSI-funded development, local key management. The 2025 0xche audit found issues but all critical ones were patched promptly. Browser extension attack surface is real but manageable. Adequate for sensitive reporting where PGP email is specifically required. For most journalist-source communication in 2026, Signal or SecureDrop is the better choice.

Who Owns This

Owner Mailvelope GmbH (Germany)

Funding Open-source project with commercial business tier. Received funding from the Open Technology Fund, Internews, and the German Federal Office for Information Security (BSI). BSI contracted Mailvelope GmbH and Intevation GmbH in 2018 to extend the extension with encrypted web forms and GnuPG key management integration.

Business model Free for personal use. Revenue from Mailvelope Business — managed deployment for organizations with Google Workspace, Microsoft 365, and Nextcloud integration. Per-user licensing with volume discounts.

Known issues

2025 audit by 0xche found seven issues: one high-severity clickjacking vulnerability in the client-API (patched in v6.1.0 by removing embeddable settings), one low-severity prototype pollution, and five informational findings including automatic WKD lookups that leak user activity to sender domains (can be disabled in settings but on by default). A signature spoofing vulnerability via OpenPGP.js was also fixed in v6.1.0. At 39C3 in late 2025, researchers presented new PGP/GnuPG vulnerabilities — not Mailvelope-specific, but affecting the underlying ecosystem. Firefox manifest v3 migration completed in v6.1.0 (May 2025). Chrome 144 compatibility fix shipped in v6.2.1 (January 2026). PGP email as a category is under pressure: cryptographers increasingly recommend against it in favor of modern E2EE protocols like Signal.

Pricing

Free for personal use. Mailvelope Business pricing is per-user with volume discounts; annual and monthly plans available. Contact sales for current rates.

This is an editorial assessment based on publicly available information as of 2026-04-02, using our published methodology. Independent security review is pending. Security posture can change at any time. This is not a guarantee of safety.

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