Proton Mail — A Swiss, end-to-end encrypted email service with zero-access encryption and open-source clients, free for 1 GB or from $3.99/month billed annually for 15 GB and custom domains.
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Best for: privacy-conscious individuals and small teams who want end-to-end encrypted email with open-source, audited clients
Pricing: Free for 1 GB; Mail Plus from $3.99/month billed annually (15 GB); Proton Unlimited from $9.99/month billed annually (500 GB plus VPN, Drive, Pass).
- Proton Mail's free plan includes 1 GB of storage and 1 email address.
- Mail Plus starts around $3.99/month billed annually (15 GB storage, 1 custom domain, 10 aliases).
- Proton Unlimited bundles Mail, VPN, Drive, Pass, and Calendar with 500 GB of pooled storage.
- Proton Mail holds a 4.5/5 rating from 122 reviews on Capterra.
- Proton Mail's client apps are open source and independently security-audited, available on web, Windows, macOS, Linux, iOS, and Android.
Limitations: Free tier storage is limited to 1 GB and one address.; Bundled VPN/Drive/Pass features raise the effective cost for email-only users.; Only 1 custom domain on the entry paid tier.
Top alternatives: Gmail, Outlook, Fastmail, Tuta, Zoho Mail — full list
What is Proton Mail?
Proton Mail is an end-to-end and zero-access encrypted email service from Proton AG, a Swiss company, built so that neither third parties nor Proton itself can read stored messages. It starts with a free plan (1 GB storage, 1 address) and scales through Mail Plus (15 GB, 10 aliases, 1 custom domain) to Proton Unlimited, which pools 500 GB of storage across Mail, Drive, and Calendar and bundles in Proton VPN and Pass. A Family plan extends Unlimited to up to 6 people with shared storage. The client apps — web, desktop (via the Bridge app for IMAP access), iOS, and Android — are open source and independently security-audited, and Proton publishes its infrastructure under Swiss data-protection law rather than US or EU jurisdiction. Proton Mail competes less on feature parity with Gmail or Outlook and more on the guarantee that Proton cannot decrypt a user's inbox even under legal compulsion.
Proton Mail is an end-to-end and zero-access encrypted email service built by Proton AG in Switzerland, aimed at privacy-conscious individuals, journalists, activists, and small teams who want a provider that cannot read their inbox. It ships a free tier with 1 GB of storage and a single address, a Mail Plus tier with 15 GB, 10 aliases, and one custom domain, and a Proton Unlimited tier that bundles 500 GB of pooled storage with Proton VPN, Drive, Pass, and Calendar. Apps are available for web, Windows, macOS, Linux, iOS, and Android, and the client code is open source and independently audited. Proton Mail differentiates on encryption architecture rather than feature breadth: zero-access encryption means Proton itself cannot read message content on any paid plan, and the desktop Bridge app lets Mail Plus and Unlimited users connect Proton Mail to standard IMAP clients like Outlook or Apple Mail. No phone number is required to sign up. Proton reports over 100 million users and 100,000+ organizations across its product family.
Standout feature: Zero-access encryption paired with open-source, independently audited client apps, so Proton itself cannot decrypt a Mail Plus or Unlimited inbox even under legal compulsion.
Biggest weakness: The free tier caps storage at just 1 GB and one address, and the higher-value Unlimited and Family tiers bundle VPN, Drive, and Pass features that email-only switchers may not need, pushing the effective per-mailbox cost above single-purpose providers like Fastmail.
Pros
- Zero-access encryption means Proton cannot read message content on any paid plan.
- Open-source, independently audited client apps across web, desktop, iOS, and Android.
- No phone number required to sign up, and Swiss jurisdiction outside US/EU data-sharing agreements.
- Bridge app connects Proton Mail to standard IMAP clients like Outlook or Apple Mail on Mail Plus and up.
Cons
- Free tier is limited to 1 GB storage and a single email address.
- Higher tiers bundle VPN, Drive, and Pass, which raises the effective price for users who only want email.
- Custom domain support starts at just 1 domain on Mail Plus, fewer than some business-focused competitors.
Proton Mail pricing
Free tier · paid from $3.99/mo
| Plan | Price | Notes |
|---|---|---|
| Proton Free | Free | 1 GB storage (expandable to 1.5 GB via onboarding tasks), 1 email address, end-to-end encryption, basic calendar. |
| Mail Plus | $3.99/mo | Billed annually (~$47.88/year); $4.99/month if billed monthly. 15 GB storage, 10 hide-my-email aliases, 1 custom domain, priority support. |
| Proton Unlimited | $9.99/mo | Billed annually (~$119.88/year); $12.99/month if billed monthly. 500 GB pooled storage across Mail, Drive, Calendar, plus Proton VPN and Pass. |
| Proton Family | $19.99/mo | Billed annually; up to 6 members sharing 3 TB total storage and all Unlimited features. |
What reviewers say
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