StartMail vs Proton Mail: Aliases, Anonymity and Sign-Up Data

Most StartMail vs Proton Mail comparisons score encryption and stop there. That is not the question people actually type. The question is how little you can hand over to open the account, and what the aliases are really doing once you have one.

Those two things pull in opposite directions, and the two providers land on opposite sides. This post scores them on sign-up data, alias mechanics, client access and storage encryption, names a winner per dimension, and is honest about the one thing neither of them sells you: anonymity.

Every capability below was checked against each vendor's own live page in September 2026. Plan contents move, so verify anything you are about to pay for on the vendor's page first.

The verdict up front#

If the goal is to open an account while revealing as little as possible, Proton Mail wins, and it is not close. Proton has a free plan, and its own verification page lists CAPTCHA as a verification option alongside email and SMS — a CAPTCHA-only path asks for nothing you own. Proton also states it does not store the email address or phone number used for verification, "only a cryptographic hash."

StartMail cannot match that, because StartMail has no free plan. It runs a 7-day trial and asks for payment details at sign-up, and says so plainly: "To prevent email abuse, we ask for payment details upon sign up." A card is an identity. That is a real concession and it decides the sign-up dimension outright.

If the goal is aliases you can actually live in, StartMail wins. Its aliases are addresses on your own mailbox rather than forwarders into it, they are unlimited, they delete cleanly, and there is a one-click burner that expires by itself. Proton's hide-my-email aliases are capped on free and Mail Plus and are managed in a second product, Proton Pass.

And if you want to read this mail in a desktop client, StartMail wins again and more decisively than most comparisons admit. StartMail publishes "Full IMAP/SMTP access." Proton requires its Bridge app, which Proton's own page says "is available only with a paid plan that includes Proton Mail."

At a glance: StartMail vs Proton Mail on aliases and sign-up#

Where StartMail wins#

StartMail's alias system is the better one for daily use, and the reason is structural rather than a feature count. A StartMail alias is another address that lands in the same mailbox. There is no forwarding hop, no second service in the path, and no separate app deciding what reaches you.

StartMail describes its aliases as "unique extra email addresses you can create and delete at any time," and advertises them as unlimited. The delete half matters more than the create half: an alias is only a spam control if killing it actually stops the mail.

The burner is the distinctive piece. StartMail's features page describes a one-click burner alias that "automatically disappears after one hour." For a download gate, a Wi-Fi portal or a one-time code, that is the right shape: you never have to remember to clean it up.

• Unlimited aliases, created and deleted from the account, with nothing to forward through.
• One-click burner aliases that expire automatically after an hour.
• Shared aliases on a custom domain, for the household or team address that several people read.
• One custom domain on the personal plan; unlimited domains on business subscriptions.

The IMAP gap is bigger than most comparisons say#

StartMail publishes "Full IMAP/SMTP access" and names Thunderbird, Outlook and Apple Mail as clients it works with. You add the account the same way you would add any other mailbox. Nothing extra runs on your machine.

Proton is architecturally different. Because message bodies are held under keys Proton cannot read, a standard IMAP client cannot decrypt them, so Proton ships Bridge — a local mail server that decrypts on your machine. Proton says Bridge "lets you add your Proton Mail account to your favorite email client via IMAP/SMTP by creating a local email server on your computer," and that it "is available only with a paid plan that includes Proton Mail."

So Proton's IMAP is paid, desktop-only, and dependent on a background process staying alive. That is a fair engineering trade for zero-access encryption, not a flaw — but if you need mail in the client you already use, on a plan you can open for free, StartMail is the one that does it.

Where Proton Mail wins#

Proton wins the dimension this post is named for. You can open a Proton account without paying, and Proton's human-verification page lists CAPTCHA as a verification method — "a short online test that confirms you're not a bot" — with the note "We don't save CAPTCHA data." Where email or SMS verification is used instead, Proton states it does not store the address or number, "only a cryptographic hash."

That is about as low as a mainstream provider's sign-up floor goes. A hash lets Proton detect a reused number without holding the number — a meaningfully different posture from keeping the number on the account. Proton is also open about why verification exists: "To protect our email reputation and prevent misuse."

Proton's free plus-addressing is the second quiet win: any Proton address takes "unlimited variations" by adding a plus symbol and a word, with no setup. That is not a privacy feature — anyone can strip the suffix to find your real mailbox — but as free per-signup tagging it is useful.

• A free plan, so no payment identity is attached to account creation.
• CAPTCHA as a verification path, with verification contact details stored only as a hash.
• Unlimited plus addressing on every plan, no setup required.
• Hide-my-email forwarding aliases that never expose the underlying mailbox address.

How Proton's hide-my-email aliases actually work#

Proton's hide-my-email aliases are forwarders, not mailbox addresses, and they live in Proton Pass rather than in Proton Mail. Proton's support documentation puts the cap at 10 aliases on Proton Free and Mail Plus, with unlimited aliases on Pass Plus, Proton Unlimited and Proton for Business plans.

The forwarding model has one real advantage over StartMail's: the alias is an address at an alias domain, so the sender never learns the mailbox it lands in. Even if the alias leaks or is sold on, what leaked is a disposable forwarder. A StartMail alias, by contrast, is a real address on your own domain or on startmail.com.

Replying is the catch. Proton documents that starting a conversation from an alias — messaging someone who has not messaged you first — is a paid-plan capability. If you need two-way correspondence from a pseudonymous address rather than just inbound receipt, that is the line to check before you commit.

Storage encryption, and what it does not cover#

Proton uses zero-access encryption for stored mail: body content and attachments sit in your mailbox under keys Proton says it cannot use. Proton is also unusually direct about the limit — its encryption page states that "subject lines, recipient email addresses, and sender email addresses are encrypted, but not end-to-end encrypted," because in OpenPGP the subject is part of a header packet that end-to-end encryption does not cover.

StartMail's approach is PGP-centred on the send side: one-click PGP encryption, PGP signatures, and password-protected messages so a recipient without PGP can still open and reply to an encrypted mail. It also documents end-to-end encryption via IMAP using OpenPGP, which is how it reconciles standard client access with encrypted content.

Jurisdiction is the axis people actually mean when they argue about this. StartMail is in the Netherlands — "your emails and data are protected by Dutch privacy legislation and GDPR," with servers in the same country and a stated policy of complying only with Dutch judicial authorities. Proton is Swiss, and says access to non-end-to-end-encrypted metadata "would require a court order that is approved by a Swiss judge."

Neither is a trump card. Both are European jurisdictions with lawful-access processes; choosing between them is a question about which legal system you would rather be adjudicated in, not about who has encryption.

Why aliases are not anonymity#

This is the part the category oversells. An alias changes what a sender sees, not what the provider sees — and the provider holds the mailbox either way.

StartMail's privacy policy is specific about the part people forget: it collects your IP address "to allow effective troubleshooting and abuse control," with web log data "stored for a maximum of 7 days after which they are deleted." A short window and a good disclosure — still a record that existed.

Payment is the other thread. StartMail says it "offers anonymous payment methods," pointing users to support for details — a route Proton does not document in the same form on the pages checked here. But a normal card payment on either service ties a billing identity to the account, and no number of aliases undoes that.

• The provider always knows which aliases belong to which account — that is how routing works.
• A card payment attaches a billing identity no alias can detach.
• Your IP is visible at connection time regardless of which address you send from.
• Writing style, signature, timing and the people you email are identifying even when the address is not.

Packaging shape, and why you should check it yourself#

This section describes packaging shape only — read the live pricing page before you buy.

StartMail is subscription-only: two tiers, personal and business, monthly or annual, with a 7-day free trial that asks for payment details up front. There is no permanent free plan. Storage is published as 20GB personal and 30GB business.

Proton is freemium: a free tier exists, and the alias, custom-domain, additional-address, pm.me and Bridge capabilities are distributed across paid tiers, with some of them living in Proton Pass rather than Proton Mail. That distribution is exactly why checking is necessary — two features that sound like one plan can sit on two.

Who each one is genuinely for#

A third option, honestly#

We build AI Emaily, and this is the section where we tell you we are not a candidate for the question this post asks. AI Emaily is a mail client with an AI agent in it. We do not issue mailboxes, we do not run an alias service, and we have no sign-up flow that competes with Proton's on data minimisation, because you bring your own mailbox to us. If you came here to choose a private mailbox provider, choose one of the two above.

Where we fit is the stage after that decision. Aliases stop mail reaching your address; they do nothing about the mail that legitimately does reach it. AI Emaily connects Gmail, Outlook and IMAP accounts into one inbox, filters cold outreach, and drafts replies you approve before anything sends, with an audit trail of what the agent did. StartMail's full IMAP/SMTP access connects straightforwardly; Proton needs Bridge, a paid-plan prerequisite on Proton's side.

Two limits worth stating in the same breath. Adding any client to an end-to-end-encrypted mailbox means mail is decrypted somewhere it can be read to be worked on — that is inherent to reading your own mail, but it is a change to the threat model you chose Proton for. And we are not free: there is no permanent free tier, only a 7-day free trial on Pro and Autopilot, card required, $0 if you cancel before day seven. The pricing page lists what each tier contains, and the AI Emaily homepage shows the product in one screen.

The short version#

Proton Mail asks for less to let you in. StartMail gives you more once you are in. Which half you weight is a question about what you are defending against — data brokers, or the provider itself.

What you should not do is treat either one as anonymity. Both are good at what they claim. Neither claims that.