Mailfence vs Mailo

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

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

Mailfence

Belgium· Email Services

Needs review

Shortlist Mailfence when you want Belgian-operated webmail with interoperable OpenPGP, digital signatures, and a light calendar/documents suite—plus optional business private-label or on-prem license. Skip when you need automatic closed E2EE without key management (consider Tuta), a large Swiss privacy ecosystem (Proton Mail), or a minimalist German mailbox (Posteo / mailbox.org).

EU-operated (Belgium)OpenPGP E2EEDigital signaturesMail + calendar + docsCustom domains (paid)B2B DPA available

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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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Highlighted rows differ between the two products.

Mailfence vs Mailo: Snapshot
Feature	Mailfence	Mailo
Country of origin	Belgium	France
Category	Email Services	Email Services
Open source	No	No
Self-hosted	No	No
Headquarters	Belgium	France
Legal entity	ContactOffice Group sa, Avenue Franklin Roosevelt 47b, B-1050 Brussels (BE 0466.241.584)	MAILO SAS (capital €75,000; RCS Créteil 851585547; VAT FR44851585547)
Governing law	Belgian law; Brussels courts (Terms of Use)	French law (terms of use)
US parent / control	No known US parent	No known US parent
CLOUD Act exposure (indicative)	Low	Medium
Hosting / residency	Primary production servers described as located in Belgium under Mailfence operational control (no intermediary managing servers per security page). No public AWS/GCP/Azure subprocessor list found. Backups stored in locations separate from offices/main DC (providers not named). Payment-card processing path not fully published.	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.
Summary	Belgian secure email suite with browser-side OpenPGP encryption, digital signatures, calendar, documents, and optional custom domains under ContactOffice Group SA.	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.
Tags	privacy saas productivity encrypted-email openpgp gdpr belgium	privacy saas productivity freemium family french webmail

At a glance: Mailfence vs Mailo
At a glance	Mailfence	Mailo
HQ / entity	Brussels — ContactOffice Group sa (BE 0466.241.584)	MAILO SAS, France (RCS Créteil 851585547)
Product launch	Mailfence brand ~2013; ContactOffice lineage since 1999	Not listed
Crypto	OpenPGP E2EE + digital signatures; optional password-encrypted messages	Not listed
Hosting	Vendor-operated servers in Belgium (per security page)	Not listed
Open source	No (front-end OSS planned; not current)	No (proprietary MailObject®)
Self-host	SaaS default; Business license for large on-prem deployments	No
Commercial model	Free tier + prepaid paid plans; Business packaging (see vendor site)	Not listed
Independent audit	No public audit PDF found	Not listed
Hosting (claimed)	Not listed	Servers in France; website host Ecritel (FR)
Model	Not listed	Freemium SaaS (Free / Premium / Pro / Junior / Edu)
Encryption default	Not listed	TLS + optional server-side PGP (not ZK E2EE)

Key capabilities: Mailfence vs Mailo
Key capabilities	Mailfence	Mailo
EU-operated (Belgium)	Yes	Not listed
OpenPGP E2EE	Yes	Not listed
Digital signatures	Yes	Not listed
Mail + calendar + docs	Yes	Not listed
Custom domains (paid)	Yes	Not listed
B2B DPA available	Yes	Not listed
France-hosted (claimed)	Not listed	Yes
Freemium webmail	Not listed	Yes
Mailo Junior	Not listed	Yes
IMAP / ActiveSync	Not listed	Yes
Pro custom domains	Not listed	Yes
Optional PGP (server-side)	Not listed	Yes

Mailfence

Browser-side OpenPGP end-to-end encryption
Encrypt outbound mail in the browser with the OpenPGP standard so intermediaries—including Mailfence when messages are properly E2EE—cannot read ciphertext. Fully interoperable with other OpenPGP tools (e.g. Thunderbird/GnuPG). Optional password-encrypted messages cover recipients who do not use PGP. Unencrypted mail still sits on servers in the normal webmail model.
Digital signatures and multi-key OpenPGP keystore
Sign messages for authenticity and integrity, and manage keys in-product: generate, import, export, publish, and hold multiple key pairs without browser plug-ins. Default generated keys are 4096-bit per the threat-model page. Passphrase protection of private keys limits crypto operations if only the account password is compromised.
Mail, calendar, documents, and groups in one account
Beyond inbox: shareable calendars, online document storage/editing, and contact groups for collaboration without bolting on a separate US suite. Storage and alias limits scale by plan; free accounts remain suitable only for light personal use.
Custom domains, aliases, and mail protocols on paid tiers
Higher plans add custom domains with SPF/DKIM/DMARC-oriented setup, larger alias counts, and classic client access (POP, IMAP, SMTP) plus ActiveSync where listed. Entry-level free accounts focus on web/PWA/apps rather than full protocol parity—verify the live plan matrix before procurement.
Business admin: API, SSO, private label, optional on-prem license
Mailfence for Business offers control-panel and XML-RPC API user provisioning, SSO and directory hooks (LDAP/AD/CAS), branding, and Belgian cloud hosting with SLA language—or a license to run on customer Linux servers for large deployments. Fit for orgs that need Belgian hosting with admin automation, not a consumer-only mailbox.

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.

Assurance & compliance: Mailfence vs Mailo
Assurance & compliance	Mailfence	Mailo
Independent security / no-logs audit	Not found No public third-party audit PDF found. Vendor mentions security specialists, bug bounty activity, and inspection openness—not a substitute for a published audit. Privacy policy documents operational metadata collection (not zero-logs).	Not found Charter claims no commercial reading of messages; automated AV/spam scanning on servers. No public third-party audit PDF found.
ISO 27001	Not found No Mailfence ISO 27001 certificate claim found on primary security/GDPR/company pages.	Not found No ISO 27001 claim found on legal/security/primary pages researched.
SOC 2 / SOC 3	Not found	Not found No SOC 2/3 report referenced on public product pages.
GDPR / EU data protection	Vendor claimed Belgian controller/processor materials; dedicated GDPR page and technical/organisational measures overview. Confirm roles in your DPA.	Vendor claimed French controller; privacy rules cite GDPR and French correspondence secrecy; DPO at dpo@mailo.com; France storage claim.
US CLOUD Act exposure (indicative)	Partial EU entity (ContactOffice Group sa), no known US parent; servers claimed self-operated in Belgium without named US hyperscaler hosts. No formal public subprocessor inventory; payment processors not named. Assessment residual: partial transparency on data path. Not legal advice.	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.
Data processing agreement (B2B)	Vendor claimed Downloadable DPA linked from the GDPR page for organisational customers.	Not found Privacy rules and terms cover processing; no standalone public B2B DPA download found—request via DPO or Pro channel.
EU AI Act	Not applicable Email/collaboration suite; not an AI system under typical procurement framing.	Not applicable Traditional email/cloud suite; not marketed as an AI system product.

Considerations & known limitations: Mailfence vs Mailo
Considerations & known limitations	Mailfence	Mailo
No public independent security audit	Medium If vendor risk requires a published audit letter, ISO 27001, or SOC 2, treat Mailfence as incomplete until evidence is obtained offline or under NDA.	Not listed
Closed-source SaaS	Medium Cannot independently review server code or default-self-host like some FOSS mail stacks. Business on-prem license is a commercial path, not community self-host docs.	Not listed
E2EE is opt-in OpenPGP, not automatic	Medium Clear-text messages are operator-readable at rest. Users must encrypt/sign deliberately; training and policy matter for regulated content.	Not listed
Operational metadata retention	Low Privacy policy lists IP, message-IDs, addresses, subjects, and related fields for operations, abuse control, and legal process—not a zero-logs design.	Not listed
Limited public subprocessor inventory	Low Strong first-party claims of internal hosting, but no AWS-style public subprocessor table; confirm payment and support tooling in procurement.	Not listed
US CLOUD Act (indicative)	Low No known US parent; Belgian self-operated hosting narrative. Residual unknown payment/SaaS paths. Not a legal safe harbour guarantee.	Not listed
PGP is server-side trusted third party	Not listed	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.
Incomplete public subprocessor inventory	Not listed	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.
US-group payment processors	Not listed	Low Checkout shares email with Verifone/Paybox; PayPal is also offered. Limited to billing path per privacy rules, but relevant to CLOUD Act diligence.
Free tier third-party advertising	Not listed	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.
No public ISO/SOC or independent security audit	Not listed	Medium Security posture relies on first-party statements and internal measures. Procurement teams may need questionnaires or NDA evidence.
Free accounts deleted after inactivity	Not listed	Low Mailo Free unused for 365 days can be deleted with content loss. Premium/Pro have different retention rules—plan backups and renewals.

Fit

Mailfence

Best fit when

You need OpenPGP interoperability and digital signatures from a European webmail, not only proprietary E2EE
Belgian legal entity and self-described self-operated Belgian hosting are procurement requirements
Teams want mail plus calendar/documents/groups without moving to Microsoft 365 or Google Workspace
You need custom domains, aliases, and classic clients (IMAP/POP/ActiveSync) on paid tiers
Business buyers evaluating private-label, API provisioning, SSO/directory integration, or large-scale on-prem license

Poor fit when

Security policy requires a published independent security audit, ISO 27001, or SOC 2 from the email vendor
You want fully open-source server/client stacks you can fork and self-host as default
Every message must be automatically E2EE with no OpenPGP key UX (Tuta-style)
You need Microsoft-class DLP, eDiscovery, compliance archives, and deep SaaS integrations
Zero-logs marketing is a hard requirement (Mailfence documents operational metadata collection)

Consider instead when

When: You want automatic encryption for all messages with minimal key management
Consider: Tuta
Different crypto model; less OpenPGP interop emphasis than Mailfence.
When: You want a larger Swiss privacy suite brand and ecosystem apps
Consider: Proton Mail
Trade Belgian ContactOffice ownership and PGP-centric UX for Proton’s broader product family.
When: You want a lean German ad-free mailbox without suite features
Consider: Posteo or mailbox.org
Simpler mailbox posture; different admin/domain/crypto tradeoffs.
When: You need full Google/Microsoft productivity and compliance tooling
Consider: Microsoft 365 or Google Workspace (accept US-cloud risk) or EU office suites if residency is the driver
Mailfence is not a drop-in M365 replacement.

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

Open questions for due diligence

Mailfence

Will Mailfence provide a current written subprocessor list (including payment processors and any backup locations) for a company account?
Is any independent security assessment available under NDA for regulated buyers?
For Business on-prem license: exact minimum scale, support model, update cadence, and cryptographic feature parity vs SaaS?
Which plan tiers currently include IMAP/POP/ActiveSync and custom-domain limits for our user count?
How are disaster-recovery backup sites jurisdictions documented in the signed DPA annex?

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?