--- title: Proton Mail canonical: https://saasranked.com/software/proton-mail/ category: Encrypted Email Services points: 85 rank: 1 of 9 facts_checked: 2026-10-08 --- # Proton Mail Swiss encrypted mailbox with a free plan, open-source apps and a paid bridge for desktop mail programs. 85 points out of 100. #1 of 9 encrypted email services. Vendor: Proton AG. Website: https://proton.me/mail - The free plan gives one mailbox with 1 GB of storage once the setup checklist is done [1]. - Mail Plus costs $3.99 a month on yearly billing and adds 15 GB and 1 custom domain [1]. - Stored messages use zero-access encryption, so Proton cannot read them [2]. - Bridge, which connects Outlook or Thunderbird, works only on paid plans [1][4]. - Proton's transparency report for 2025 counts 9,301 legal orders for Proton Mail [3]. Verdict: Proton Mail suits people who want zero-access storage, a free starter mailbox and open-source apps [1][2][6]. Mail Plus at $3.99 a month adds a custom domain and Bridge for desktop mail programs [1][4]. The catch: Bridge is paid-only, the Linux app is still beta, and no outside audit of the mail apps dated 2024 or later is named on the vendor's open-source page [1][4][5]. Best for: People who want a free encrypted mailbox that grows into a paid one with custom domains and Outlook or Thunderbird access. ## Points | Criterion | Line | Value | Points | Note | |---|---|---|---|---| | Encryption | Stored mail the provider cannot read | Yes | 10/10 | Proton says messages and attachments in the inbox use zero-access encryption, so nobody, not even Proton, can access them [2]. | | Encryption | Automatic end-to-end encryption between its own users | Yes | 8/8 | Proton says messages between Proton Mail addresses are always end-to-end encrypted [2]. | | Encryption | Encrypted mail to other providers | Yes | 6/6 | Password-protected emails send end-to-end encrypted messages to non-Proton addresses [2]. | | Encryption | Encrypted contacts or calendar | Yes | 3/3 | Proton says Calendar event details are end-to-end encrypted so Proton cannot see them [10]. | | Trust and audits | Independent audit since 2024 | Not published | 0/8 | The open-source page links audit reports but names no firm or date [5]; the named Securitum audit is dated 2021 [11]. | | Trust and audits | Open-source apps | Yes | 6/6 | Proton says all its apps are open source; the web clients are on GitHub under GPL-3.0 [5][6]. | | Trust and audits | SOC 2 Type II or ISO 27001 | Yes | 4/4 | Proton received ISO 27001 certification on 2 May 2024, covering its information security management systems [9]. | | Trust and audits | Transparency report | Yes | 4/4 | The report gives Proton Mail legal order counts for 2025: 9,301 orders, 988 contested [3]. | | Trust and audits | Security key for two-factor sign-in | Yes | 4/4 | Proton accepts a physical U2F or FIDO2 security key for two-factor sign-in, on free and paid plans [7]. | | Apps and access | Official apps | Windows, macOS, iOS, Android | 8/10 | Download page lists Windows, macOS, iOS and Android apps; the Linux app is labelled beta, so it does not count [4]. Free accounts get a 14-day desktop trial [13]. | | Apps and access | Works in standard mail programs | Yes | 8/8 | Bridge, Proton's own desktop app, links paid accounts to Outlook, Thunderbird and Apple Mail [1][4][12]. | | Mailbox | Your own domain | Yes | 5/5 | Mail Plus supports 1 custom domain; Unlimited supports 3 [1]. | | Mailbox | Mail storage on the cheapest paid plan | 15 | 4/5 | Mail Plus, the cheapest paid plan, has 15 GB [1]. | | Mailbox | Export your whole mailbox | Yes | 3/3 | The Export Tool saves all emails as EML files with JSON metadata; Bridge also copies the mailbox to a mail program [8]. | | Price | Free plan with an encrypted mailbox | Yes | 6/6 | The free plan includes one mailbox; Proton says it will always offer a free plan [1]. | | Price | Cheapest paid plan | $3.99/mo | 6/10 | Mail Plus, $3.99 a month on yearly billing, shown as 20% off the $4.99 monthly price; no renewal price is shown [1]. | ## Plans | Plan | Price | Per month (USD) | |---|---|---| | Free | Free [1] | $0 | | Mail Plus | $47.88/year [1][4] | $3.99 | | Proton Unlimited | $119.88/year [1] | $9.99 | Prices are shown in US dollars, before tax. The pricing page lists only 1-month and 12-month billing [1]. ## Strengths - Documents zero-access encryption of stored mail and encrypted calendar events [2][10]. - Sends password-protected encrypted mail to people on other providers [2]. - The transparency report covers 2025 and gives order counts [3]. - Names an ISO 27001 certification, dated May 2024 [9]. - Physical U2F or FIDO2 security keys protect sign-in [7]. ## Limits - Free storage is 500 MB, rising to 1 GB after a setup checklist [1]. - Bridge for desktop mail programs needs a paid plan [1][4]. - The Linux app is labelled beta [4]. - Subject lines and email addresses are not end-to-end encrypted [2]. - Free accounts can try the Windows and macOS desktop apps for 14 days; after that they need a paid plan [13]. ## Vendor claims (not scored) - Proton says all its apps are open source and independently audited by third-party experts [5]. ## Sources 1. [Proton Mail pricing](https://proton.me/mail/pricing), Proton, accessed 2026-10-08 2. [Proton Mail encryption explained](https://proton.me/support/proton-mail-encryption-explained), Proton, accessed 2026-10-08 3. [Transparency report](https://proton.me/legal/transparency), Proton, accessed 2026-10-08 4. [Get Proton Mail apps](https://proton.me/mail/download), Proton, accessed 2026-10-08 5. [Open source and audits](https://proton.me/community/open-source), Proton, accessed 2026-10-08 6. [ProtonMail/WebClients](https://github.com/ProtonMail/WebClients), GitHub, accessed 2026-10-08 7. [Two-factor authentication (2FA)](https://proton.me/support/two-factor-authentication-2fa), Proton, accessed 2026-10-08 8. [Export emails with the Proton Mail Export Tool](https://proton.me/support/export-emails-import-export-app), Proton, accessed 2026-10-08 9. [Proton achieves ISO 27001 certification](https://proton.me/blog/iso-27001-certification), Proton, accessed 2026-10-08 10. [Proton Calendar](https://proton.me/calendar), Proton, accessed 2026-10-08 11. [Security audit](https://proton.me/blog/security-audit), Proton, accessed 2026-10-08 12. [Install Proton Mail Bridge](https://proton.me/support/protonmail-bridge-install), Proton, accessed 2026-10-08 13. [Proton Mail desktop app](https://proton.me/support/mail-desktop-app), Proton, accessed 2026-10-08