Proton Mail vs Tuta for Encrypted Email: Which Protects More?

If the question is literally which service encrypts more bytes of your mail end-to-end between two accounts on the same provider, Tuta wins on that dimension and it is not particularly close. Tuta encrypts subject lines, calendar events with times and locations, the address book, inbox rules and even the search index. Proton Mail, by design, leaves subject lines unencrypted because it adheres to the OpenPGP standard, where the subject sits in the header packet outside the encrypted payload.

That single fact decides one axis of the comparison. It does not decide the whole thing. Proton wins interoperability outright because OpenPGP is what the rest of the encrypted email world speaks, and it wins client access because Proton Bridge exposes an IMAP and SMTP endpoint that Apple Mail, Outlook or Thunderbird can connect to. Tuta's mailbox lives inside Tuta's own apps and its own protocol. Both trade-offs are legitimate. Which one is right for you depends on whether your threat model cares more about what a subpoena to the mail server would reveal, or about being able to send an encrypted message to someone who does not use your provider.

The verdict: which encrypts more of your email?#

Tuta encrypts more of the message content. Between two Tuta accounts, the subject line, body, attachments, calendar entries with their descriptions and locations, and the contact list are all end-to-end encrypted on the client before they ever reach Tuta's server. The search index that lets you find those messages later is encrypted on the client too. Proton Mail encrypts the body and attachments end-to-end between Proton accounts, but the subject line is stored unencrypted in Proton's model, because OpenPGP places the subject in the header packet outside the encrypted payload.

Proton wins the surrounding parts of the same question. OpenPGP is a published, audited standard (RFC 4880), so a Proton user can send an encrypted message to any correspondent with a PGP key and any correspondent with a PGP key can decrypt a Proton message. Tuta's end-to-end encryption only works between Tuta accounts; anyone outside the Tuta ecosystem gets a password-protected link instead of a PGP payload their own client can read. Proton also lets you use Apple Mail, Outlook or Thunderbird through Proton Bridge; Tuta does not offer an IMAP or SMTP endpoint at all.

So the honest one-line answer is that Tuta encrypts more of the message itself and Proton makes what it does encrypt travel further. If you never plan to send encrypted mail to anyone outside your provider and you want the subject line hidden, Tuta is the stronger fit. If you need OpenPGP interoperability, or you want your encrypted mailbox to show up in the client on your desk that you already use for everything else, Proton is the stronger fit. Neither product is dishonestly winning on the axis the other picks.

Proton Mail vs Tuta at a glance#

The table below sticks to documented capabilities. Both vendors publish their encryption models and roadmap on their own sites, so verify any dated claim against those pages before you commit to a plan — the two products ship changes often, and post-quantum cryptography in particular is moving quickly on both sides.

Two entries in that table deserve their honesty called out. Sender and recipient email addresses are not on either row because neither provider can encrypt them — SMTP has to see the envelope to route the mail. That is a limit of the protocol, not of either product, and any encrypted-email service that claims to encrypt the To/From line is either mislabelling in-transit TLS as end-to-end or hiding something specific inside a subject header that still leaks in transit. Both Proton and Tuta are careful about this in their own docs; a review site that says one of them encrypts the envelope is wrong.

Where Proton Mail wins#

Proton's biggest win is that it speaks the standard everyone else in the encrypted-email world speaks. OpenPGP has been an IETF standard since 1998 (RFC 4880) and it has decades of client support behind it — Thunderbird, GPGTools, Kleopatra, mailvelope, enterprise mail-security gateways. A Proton user can send an encrypted, signed message to a security researcher who has never heard of Proton and that researcher can read it in the mail client they already use, because the encryption is not tied to the provider. Tuta's proprietary scheme does not have that reach and probably never will, because a proprietary protocol only lives where its vendor's client runs.

The second real win is Proton Bridge. Bridge runs on your desktop, opens a local IMAP and SMTP endpoint on 127.0.0.1, and translates between that endpoint and Proton's encrypted API. That means you can point Apple Mail, Outlook or Thunderbird at your Proton mailbox and use it exactly like any other IMAP account — search, rules, unified inbox, all of it — while the encryption happens on your machine. If you want an encrypted mailbox but you do not want to give up the client on your Mac or the extensions in Thunderbird you have used for a decade, this is a real advantage that Tuta does not attempt to match.

The third is the broader Proton stack. Proton VPN, Proton Drive, Proton Calendar, Proton Pass and Proton Wallet share the same account and, on paid plans, the same subscription. That is a genuinely different product than an encrypted mail service on its own, and if you are consolidating away from Google Workspace or iCloud+ for the same set of jobs, having them one login apart is a legitimate reason to choose Proton for the mail piece.

We should be honest about the shape of the concession here, because it is the single most important paragraph on this page. Proton's OpenPGP-native design has more mature interoperability and more mature client support than Tuta's proprietary encryption ever will, by construction. That is not a Tuta failing so much as the structural cost of doing your own protocol: it lets Tuta encrypt more of the message, and it stops that encryption at the edge of Tuta's own product. If a reader's threat model puts OpenPGP interoperability first, Proton wins on this dimension outright and it is not close.

Where Tuta wins#

Tuta's biggest win is that it encrypts things Proton chose not to. Subject lines, calendar events with their descriptions and locations, the entire address book and even the client-side search index all get end-to-end encrypted between Tuta accounts. If a court order arrives at Tuta's server, the payload the server can hand over is closer to opaque ciphertext than the same order served on any provider that leaves subjects and calendar entries in plaintext. That is the axis Tuta was built to win on, and on that axis it does.

The second real win is the post-quantum roadmap. Since March 2024, Tuta has been rolling out TutaCrypt, a hybrid scheme that combines existing elliptic-curve cryptography with a Kyber-based key encapsulation designed to resist attacks by a future large-scale quantum computer — the so-called "harvest now, decrypt later" scenario, where an adversary stores today's encrypted mail and waits for the maths to break. Proton has published its own work in this area on its blog, and both should be checked against their current pages, but Tuta shipped a user-facing implementation earlier and it is worth naming.

The third is that Tuta's stack is fully open source, client and server, and the company controls the whole path from browser to disk. There is no Google reCAPTCHA on the login page, no third-party analytics, no external CDN doing the delivery. That is a different threat-model choice than Proton makes, and for a reader who cares about the number of parties involved in loading their inbox at all, it is a real one.

The tradeoff on the Tuta side is the mirror image of the Proton concession above: encrypting the subject line is only possible because Tuta does not have to make that subject readable to a PGP client that expects it in the header. If your correspondents live outside Tuta, the encryption stops at Tuta's edge and they get a password-protected web link, not an OpenPGP payload their own client can decrypt in place. Both halves of that trade are real, and you cannot have both at once inside one product.

How the two price, without the numbers#

Neither vendor's pricing is stable enough to quote here — both have refactored their plans in the last twelve months, and either could do it again before this page is a month old. What we can describe honestly is the shape of the packaging, because that has been consistent, and then send you to the current page.

Proton Mail is packaged as a free tier plus paid personal plans (Proton Mail Plus and Proton Unlimited) plus family and business plans. The interesting move is Proton Unlimited, which bundles Mail with Drive, VPN, Pass, Calendar and Wallet under one subscription — that changes the pricing question from "how much is the mailbox" to "how much is a whole encrypted stack replacement for Google or iCloud+." Custom domains, more aliases and Proton Bridge sit above the free tier. Annual billing is meaningfully cheaper than monthly, and there are lifetime-style long-term commitments that show up periodically.

Tuta is also packaged as a free tier plus paid personal plans (currently Revolutionary and Legend) plus family, team and business plans. The comparable move on Tuta's side is that the calendar and encrypted contacts are part of the mail product itself rather than a separately-priced app; if you specifically want encrypted calendar and address book, you are not paying for a whole bundle to get them. Paid tiers add custom domains, more aliases, more storage and search across your entire mailbox rather than a limited window.

Who Proton Mail is genuinely for#

Proton is the right choice if any of these describe you. You need to send encrypted mail to correspondents who do not use your provider, so OpenPGP interoperability is not optional. You want to keep using Apple Mail, Outlook or Thunderbird as your mail client, so a local IMAP endpoint via Proton Bridge is a hard requirement. You are consolidating away from Google Workspace or iCloud+ and you want VPN, Drive, Calendar and Pass under the same account so the migration is one login change and not five. You care that the subject-line trade-off exists but you are willing to live with it in exchange for standard-based encryption.

Proton is the wrong choice if what actually matters to you is that the subject line and the calendar entries themselves get encrypted, or if you are unwilling to run a separate Bridge process on your desktop for the mail-client use case. Those are exactly the axes Tuta was built to win on, and forcing Proton onto them just to end up on the more popular product would be picking the wrong tool for your threat model.

Who Tuta is genuinely for#

Tuta is the right choice if any of these describe you. You want the subject line, the calendar event descriptions and the contact list themselves end-to-end encrypted, not just the message body. You are willing to live inside Tuta's own apps on desktop, web and mobile, because your correspondents will either be on Tuta too or will receive a password-protected link. You want the whole stack — client and server — open source, and you want a shorter list of third parties involved in loading your inbox. You take the post-quantum "harvest now, decrypt later" threat model seriously and you want a provider that has shipped user-facing work on it, not just written blog posts.

Tuta is the wrong choice if you need OpenPGP interoperability with correspondents outside the service, if you want to use Apple Mail or Outlook as your client, or if you are trying to replace a bundle like Google Workspace where the calendar and drive and password manager need to live under the same subscription. On those axes Proton is the honest recommendation and it is not close.

A third option, honestly: an AI mail client#

Some readers land on this page because they want stronger encryption, and some land on it because they want any mail product that is not the one they are on today. If your real question is closer to the second — you are tired of your inbox and encrypted mail is one of the shortlists you clicked into — it is worth naming that the encrypted-email category and the AI-mail-client category are not the same category, and neither Proton nor Tuta is trying to compete on the second one.

We build AI Emaily, which is an AI-native mail client for triage, drafting, follow-ups and audit trails on Gmail, Outlook and standard IMAP mailboxes. It is not encrypted-email infrastructure and it does not replace Proton or Tuta. It also does not, as of this writing, connect through Proton Bridge or Tuta's proprietary protocol — Bridge is technically an IMAP endpoint but is not a supported provider on our side, and Tuta does not expose IMAP or SMTP at all. So if you have picked Proton or Tuta specifically because the encryption model is what you want, AI Emaily is not the right shortlist for that mailbox.

If, on the other hand, your Gmail or Outlook account is where the actual work happens and encrypted mail is a side channel for the small share of correspondence that needs it, running AI Emaily on the main inbox and keeping a separate Proton or Tuta account for the encrypted thread is a common pattern and a legitimate one. That is the shape of the honest third-option recommendation on this page: not "use us instead of the encrypted provider," but "if you want an AI-native client for the mailbox you actually live in, that is what we do — how much it costs and the free trial are on our pricing page."

The bottom line#

The primary keyword on this page is proton mail vs tuta for encrypted email, and the primary reader is trying to decide between two products that both have a real answer to give. Tuta encrypts more of the actual message, including the subject line and the calendar and the contacts. Proton encrypts less inside the message and makes what it does encrypt reach further, through OpenPGP interoperability and Proton Bridge. Both trade-offs are legitimate. Pick the one whose trade lines up with what you actually plan to do, verify current pricing and current post-quantum status on each vendor's own page before you pay, and do not let a third-party comparison quote you a number that has drifted since it was written.