Mailo vs Proton Mail

Compare Mailo and Proton Mail on capabilities, jurisdiction, assurance, and fit for European buyers.

Both listed as alternatives to: Gmail, Microsoft 365, Outlook.com

Mailo

France· Email Services

Needs review

Shortlist Mailo when you want French-entity freemium webmail with classic IMAP/EAS clients, integrated calendar/cloud, supervised Mailo Junior for kids, or Pro custom domains for SMEs—without US Big Tech accounts. Skip when you need default zero-knowledge E2EE, open-source/self-host, or a full Workspace-class suite; consider Tuta, Proton Mail, or Infomaniak kMail instead.

France-hosted (claimed)Freemium webmailMailo JuniorIMAP / ActiveSyncPro custom domainsOptional PGP (server-side)

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Proton Mail

Switzerland· Email Services

Needs review

Shortlist Proton Mail when you want Swiss-jurisdiction, zero-access encrypted email with open-source clients, custom domains, Bridge for desktop mailers, and a public DPA. Skip when you need free-tier IMAP Bridge, fully self-hosted FOSS mail on your own servers, or Workspace-class collaboration depth—consider Tuta, Posteo, or Mailfence among EU peers, or stay on Google/Microsoft if suite lock-in wins.

E2EE + zero-accessSwiss-operatedBridge (IMAP/SMTP)Open-source clientsISO 27001 & SOC 2 (claimed)Public B2B DPA

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Highlighted rows differ between the two products.

Mailo vs Proton Mail: Snapshot
Feature	Mailo	Proton Mail
Country of origin	France	Switzerland
Category	Email Services	Email Services
Open source	No	No
Self-hosted	No	No
Headquarters	France	Switzerland
Legal entity	MAILO SAS (capital €75,000; RCS Créteil 851585547; VAT FR44851585547)	Proton AG, Route de la Galaise 32, 1228 Plan-les-Ouates, Geneva, Switzerland (EU representative: Proton Europe sàrl, Luxembourg)
Governing law	French law (terms of use)	Swiss law (Terms; Geneva courts for business/non-US consumer disputes as stated in Terms)
US parent / control	No known US parent	No known US parent
CLOUD Act exposure (indicative)	Medium	Medium
Hosting / residency	Vendor states user personal data and content are stored/processed on servers in France; specialised French host centre (who-we-are); website hosted by Ecritel, Arradon, France. Named third parties: Verifone/Paybox (payment email), PayPal option, Gandi/Netim (domains), Sirdata + ad agencies (free-tier ads), optional Rainbow video and OnlyOffice. Full mail DC/backup subprocessor list not published.	Primary mail storage on Proton-owned servers in Switzerland (vendor security pages). Not marketed as AWS/GCP/Azure inbox hosting. Public privacy policy lists US-group processors for support and payments (Zendesk; Chargebee, Stripe, PayPal) and group support processing in North Macedonia and Taiwan; HubSpot noted for business sales inquiries.
Summary	French freemium webmail and Mail&Cloud suite (MAILO SAS): email, calendar, cloud disk, Mailo Junior for children, and Pro custom domains—hosted in France, proprietary SaaS.	Swiss end-to-end encrypted email from Proton AG: zero-access inbox storage, open-source clients, custom domains, and Bridge for desktop IMAP clients.
Tags	privacy saas freemium family french webmail productivity	privacy saas encryption e2ee switzerland business free-tier open-source-clients

At a glance: Mailo vs Proton Mail
At a glance	Mailo	Proton Mail
HQ / entity	MAILO SAS, France (RCS Créteil 851585547)	Not listed
Hosting (claimed)	Servers in France; website host Ecritel (FR)	Not listed
Model	Freemium SaaS (Free / Premium / Pro / Junior / Edu)	Not listed
Open source	No (proprietary MailObject®)	Not listed
Self-host	No	No (SaaS); clients open source
Encryption default	TLS + optional server-side PGP (not ZK E2EE)	Not listed
HQ	Not listed	Plan-les-Ouates (Geneva), Switzerland
Legal entity	Not listed	Proton AG (CHE-354.686.492); Proton Foundation supervision
Hosting model	Not listed	Proton-owned hardware in Switzerland (vendor claim)
Commercial model	Not listed	Freemium + paid consumer and business seats
Bridge	Not listed	Paid plans that include Mail

Key capabilities: Mailo vs Proton Mail
Key capabilities	Mailo	Proton Mail
France-hosted (claimed)	Yes	Not listed
Freemium webmail	Yes	Not listed
Mailo Junior	Yes	Not listed
IMAP / ActiveSync	Yes	Not listed
Pro custom domains	Yes	Not listed
Optional PGP (server-side)	Yes	Not listed
E2EE + zero-access	Not listed	Yes
Swiss-operated	Not listed	Yes
Bridge (IMAP/SMTP)	Not listed	Yes
Open-source clients	Not listed	Yes
ISO 27001 & SOC 2 (claimed)	Not listed	Yes
Public B2B DPA	Not listed	Yes

Mailo

French-hosted webmail with IMAP, EAS, and classic protocols
Webmail plus IMAP4 for clients, Exchange ActiveSync for mobile sync, and POP3 on paid tiers; SMTP relay with account credentials. Vendor states mail and content stay on servers in France. Free tier is ad-supported with lower quotas; Premium unlocks POP3, more aliases, and larger mail/cloud caps. Suits teams that need standard desktop/mobile clients rather than a closed proprietary app only.
Mailo Junior supervised email for children
Child accounts (about ages 6–14) only exchange mail with contacts a parent or teacher validates. Age-adapted mini/junior UIs, no ads on Junior, optional promotion to a standard account while keeping the address. Separate Junior mobile apps. Unique fit for families and schools versus generic consumer mail.
Calendar, virtual disk, and open sync protocols
Shared calendars and tasks, address book, photo albums, and a virtual disk for files with WebDAV/FTP access. CalDAV and CardDAV for external clients. Premium+ can unlock OnlyOffice in-browser editing. Better as an all-in-one Mail&Cloud for SMEs/families than bare IMAP-only privacy mail.
Mailo Pro spaces: custom domains and mutualised storage
Pro Start/5/Modulo style plans share mail+cloud quota across accounts, support custom domains (register, transfer, or declare external), distribution lists, mailbox sharing, resource calendars, and manager tooling. Priority Pro hotline with documented acknowledgement and restoration targets for Pro subscriptions. Aimed at TPE/PME, associations, and municipalities—not a full Google Workspace clone.
Optional server-side PGP and account security controls
Built-in PGP/MIME encrypt and sign in the webmail as a trusted third party (keys managed on Mailo for multi-device convenience). Two-factor authentication, application passwords, connection history, and guardianship-style access options. Not zero-knowledge E2EE by default—use external client crypto if the provider must never hold keys.

Proton Mail

Zero-access inbox encryption by default
Bodies and attachments are encrypted so Proton states it lacks keys to read stored mail. Proton-to-Proton traffic is end-to-end encrypted automatically; external recipients need password-protected messages or PGP/WKD for comparable content protection. Subject lines are not fully E2EE under OpenPGP header rules.
Proton Mail Bridge for desktop IMAP clients
Paid plans that include Mail can run Bridge locally to connect Outlook, Thunderbird, or Apple Mail over IMAP/SMTP while encrypting and decrypting on the device. Free accounts use official web/mobile/desktop apps instead of Bridge.
Custom domains, aliases, and business admin
Paid and business tiers support custom domains, extra addresses, catch-all and groups, hide-my-email aliases, and org admin for seats, storage, and retention policies. Suits teams leaving Google/Microsoft who still need branded addresses.
Open-source clients with published audits
Web, mobile, and desktop clients are published on GitHub with third-party audit reports linked from Proton’s open-source page. The hosted mail backend is not offered as self-hosted FOSS—audit client trust, not full server reproducibility.
Tracker blocking, PhishGuard, and Sentinel
Built-in tracker protection, phishing heuristics, link confirmation, SPF/DKIM/DMARC for custom domains, hardware-key 2FA, and optional Proton Sentinel monitoring for high-risk accounts. Complements encryption with everyday abuse defenses.

Assurance & compliance: Mailo vs Proton Mail
Assurance & compliance	Mailo	Proton Mail
Independent security / no-logs audit	Not found Charter claims no commercial reading of messages; automated AV/spam scanning on servers. No public third-party audit PDF found.	Vendor claimed Open-source clients with published third-party audit reports (web/desktop links on open-source page). Not a classic VPN no-logs court test; transparency report covers legal orders for accessible account data.
ISO 27001	Not found No ISO 27001 claim found on legal/security/primary pages researched.	Vendor claimed Vendor announces ISO 27001 certification after external audit completed 2 May 2024; Trust Center links a certificate download. Confirm scope and validity at procurement time.
SOC 2 / SOC 3	Not found No SOC 2/3 report referenced on public product pages.	Vendor claimed Vendor announces first SOC 2 Type II attestation (July 2025 blog). Report typically under NDA—request from vendor for diligence files.
GDPR / EU data protection	Vendor claimed French controller; privacy rules cite GDPR and French correspondence secrecy; DPO at dpo@mailo.com; France storage claim.	Vendor claimed Swiss controller/processor with EU representative; public DPA; GDPR materials for business. Adequacy/transfer mechanisms documented for non-adequate destinations.
US CLOUD Act exposure (indicative)	Partial EU entity / no known US parent / France-claimed mail hosting, but Verifone and PayPal (US-group) on payment path; full infra subprocessors unpublished. Assessment only—not legal advice.	Partial Swiss entity / no known US parent; inbox content on Proton-owned Swiss hardware with zero-access design. Partial exposure remains via US SaaS subprocessors (Zendesk support; Stripe/Chargebee/PayPal payments) and any account metadata Proton can access under Swiss process. Not legal advice.
Data processing agreement (B2B)	Not found Privacy rules and terms cover processing; no standalone public B2B DPA download found—request via DPO or Pro channel.	Vendor claimed Public DPA at proton.me/legal/dpa forms part of terms when Proton acts as processor; Swiss law, Geneva jurisdiction; general authorization for listed subprocessors.
EU AI Act	Not applicable Traditional email/cloud suite; not marketed as an AI system product.	Not applicable Core product is encrypted email. Optional Scribe assistant is ancillary; not an AI-centric offering for this catalog entry.

Considerations & known limitations: Mailo vs Proton Mail
Considerations & known limitations	Mailo	Proton Mail
PGP is server-side trusted third party	Medium Webmail PGP holds keys on Mailo for multi-device use. Provider-access risk differs from zero-knowledge E2EE defaults at Tuta/Proton. Use external crypto if that is a hard requirement.	Not listed
Incomplete public subprocessor inventory	Medium Privacy rules name payments, domains, and free-tier ads, but not a full list of mail storage, backup, or anti-spam infrastructure vendors. Request annex for B2B risk review.	Not listed
US-group payment processors	Low Checkout shares email with Verifone/Paybox; PayPal is also offered. Limited to billing path per privacy rules, but relevant to CLOUD Act diligence.	Not listed
Free tier third-party advertising	Low Mailo Free shows ad banners via agencies under IAB TCF consent (Sirdata CMP). Premium removes ads. Ad cookies stated as not tied to Mailo profile.	Not listed
No public ISO/SOC or independent security audit	Medium Security posture relies on first-party statements and internal measures. Procurement teams may need questionnaires or NDA evidence.	Not listed
Free accounts deleted after inactivity	Low Mailo Free unused for 365 days can be deleted with content loss. Premium/Pro have different retention rules—plan backups and renewals.	Not listed
Weaker defaults outside Proton	Not listed	Medium Mail to Gmail/Outlook/others is not E2EE unless password-protected or PGP/WKD is used. Subject lines are not fully E2EE. Train users or you only protect the Proton-stored copy.
US support and payment processors	Not listed	Medium Zendesk, Chargebee, Stripe, and PayPal appear in the public processor list. They should not see zero-access message bodies, but support content and billing data can touch US-group services—document this in DPIAs.
Bridge requires paid Mail	Not listed	Low Desktop IMAP/SMTP via Bridge is not available on free accounts. Budget seats for users who refuse the official apps.
Hosted service, not self-hosted FOSS mail	Not listed	Medium Open-source clients improve inspectability but you still depend on Proton’s operated backend, uptime, and Swiss legal process. Unsuitable if policy mandates customer-operated mail servers.
Swiss legal orders on accessible data	Not listed	Low Transparency reports show thousands of yearly legal orders for Mail with many complied. Bodies stay encrypted; recovery emails, IPs (when retained for abuse), and similar metadata may still be in scope. Align expectations with counsel.

Fit

Mailo

Best fit when

EU individuals and families wanting French-hosted mail with calendar and cloud disk in one account
Parents/schools needing supervised child email (Mailo Junior) with contact allow-lists
French SMEs, associations, and municipalities needing custom domains and mutualised Pro storage
Teams that depend on IMAP, EAS, CalDAV, CardDAV, or WebDAV rather than a locked-in app
Buyers who accept freemium ads on free tier or low-cost Premium rather than pure prepaid anonymity mail

Poor fit when

Orgs that require default end-to-end encryption with zero-access provider architecture
Buyers that need open-source server code or official self-hosting
Enterprises needing SOC 2 / ISO 27001 evidence already published on a trust centre
Heavy Google Workspace / Microsoft 365 collaboration suites (docs/drive ecosystem depth)

Consider instead when

When: You need zero-knowledge / default E2EE webmail
Consider: Tuta or Proton Mail
Mailo PGP is optional and server-side trusted third party
When: You want German privacy mail with different encryption/product posture
Consider: Posteo or mailbox.org
Compare protocols, storage bundles, and business features side by side
When: You need Swiss multi-product cloud with mail plus broader suite
Consider: Infomaniak kMail
Different country stack and product breadth
When: You need US Big Tech ecosystem integration at any cost
Consider: Gmail or Microsoft 365 / Outlook.com
Trade EU entity and France residency claims for ecosystem depth

Proton Mail

Best fit when

Teams that need default end-to-end / zero-access encryption without running their own mail stack
Orgs that want Swiss legal venue and documented resistance to direct foreign data demands
Businesses migrating branded domains off Gmail/Outlook with Easy Switch and Bridge for desktop holdouts
Security-conscious professionals who value open-source clients, published audits, and hardware-key 2FA
Buyers who need a public DPA plus vendor-claimed ISO 27001 / SOC 2 Type II for questionnaires

Poor fit when

Fully self-hosted requirements (Proton Mail is SaaS; clients are open source, not a full on-prem mail server)
Desktop IMAP on free accounts only—Bridge needs a paid plan that includes Mail
Workflows that depend on unencrypted-looking mail to external parties who will not use password links or PGP
Teams that primarily need full Microsoft 365 / Google Workspace collaboration depth rather than encrypted mail first

Consider instead when

When: You want German E2EE email with a different crypto product surface and may not need Proton’s full ecosystem
Consider: Tuta
Compare desktop interoperability and business admin maturity side by side.
When: You want ad-free European mail with strong transport privacy but do not require zero-access E2EE for all stored content
Consider: Posteo
Different threat model: Posteo is privacy-forward without Proton’s zero-access default.
When: You need OpenPGP-centric mail with classic collaboration extras under Belgian operation
Consider: Mailfence
Weigh automatic Proton-to-Proton E2EE UX versus Mailfence’s model.
When: Collaboration suite depth and ecosystem lock-in outweigh encryption defaults
Consider: Google Workspace or Microsoft 365
Accept US-provider jurisdiction and scanning/processing models as tradeoffs.

Open questions for due diligence

Mailo

Will Mailo sign a GDPR Article 28 DPA with a full subprocessor and transfer annex for Pro customers?
What is the named primary data-centre operator and backup/DR location beyond the France and Ecritel website-host statements?
Is there an independent penetration test, ISO 27001 roadmap, or customer-available security whitepaper?
Where is Rainbow (video) and OnlyOffice data processed relative to the France mail claim?
Current UGAP / public procurement listing status for French public buyers?

Proton Mail

What exact data-center sites and any non-Swiss regions apply to your tenant’s mailbox replicas today?
Will Proton provide the full SOC 2 Type II report under NDA and confirm ISO 27001 certificate scope/expiry for your questionnaire?
For business orgs: which users will be private vs non-private, and how will admin recovery work with zero-access constraints?
Which external partners must receive E2EE content, and will they accept password-protected messages or PGP?