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Business Email & Office Suites

mailbox.org Business

EU-Made Report an error

Panel rating · 6 judges · How to read the stars

Category median

Sovereignty: not determined

0–5 in half steps. 5 means the rubric's top anchor is met on the evidence.

by Heinlein Hosting GmbH · mailbox.org

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Add ?theme=dark to the image address for dark backgrounds. The badge shows the category and the month of the latest evaluation, and EU-Made where that is the product’s provenance. It never shows a score.

mailbox.org Business at a glance

Vendor
Heinlein Hosting GmbH
Headquarters
Not stated on the vendor’s pages as of 5 Nov 2026
Data hosting
Default not stated; pages mention Germany source, captured 5 Nov 2026
Free plan
Not stated on the vendor’s pages as of 5 Nov 2026
Panel verdict
The AI panel rates mailbox.org Business 3/5, the mean of 6 judges. mailbox.org Business, operated by Heinlein Hosting GmbH, bundles mail (webmail, IMAP, POP3), calendar, contacts, browser office editing, drive and video meetings, with servers stated to stand exclusively in Berlin. how scores are made
As of
Vendor pages captured 5 Nov 2026; evaluated by the panel 6 Nov 2026. all sources

mailbox.org Business alternatives, European ones first →

Read this page as one judge. Each weighs the same scores by what they care about.

The Small Firm Owner

Weighted verdict

Runs a tax and accounting firm of twelve in Lower Saxony. Every member of staff lives in Outlook, the shared "kanzlei@" mailbox is the busiest address in the office, and the meeting room is booked by shouting across the corridor. Wants mail on the firm's own domain that arrives, a shared calendar and address book on every phone, a move from the old provider that does not lose a single client thread, and a per-user price that is still the price in the second year.

Same scores as the panel view — this lens weights them the way this judge cares.

Scored by The Small Firm Owner

Panel median The Small Firm Owner This judge’s scores over the panel median. Each label opens its reasoning below.
Scores per criterion, in stars out of 5
Criterion Panel median The Small Firm Owner
Mail, domains & deliverability 3.5 of 5 3.5 of 5
Calendar, contacts & office apps 3.5 of 5 3.5 of 5
Security, encryption & compliance archiving 3.5 of 5 3.5 of 5
Administration, identity & partner management 3 of 5 3.5 of 5
Migration, open standards & exit 3 of 5 3 of 5
European sovereignty 3.5 of 5 3.5 of 5
Pricing transparency 3.5 of 5 3.5 of 5

Mail, domains & deliverability

How this is scored

How well the mailbox itself works: custom domains and their DNS set-up, aliases, catch-all, shared and functional mailboxes, distribution lists, mailbox and attachment size limits, IMAP, POP3, SMTP and Exchange ActiveSync or MAPI for Outlook, web and mobile apps, spam and malware filtering, SPF, DKIM, DMARC and MTA-STS, out-of-office and server-side rules, send limits, and the delivery reputation of the sending infrastructure. A self-hosted groupware is judged on the mail server it ships; a suite whose mail app is only a client for another server scores at the level of that client.

0 — No mailbox at all; a product that only sends transactional mail or only reads another provider's mail without a server of its own or a documented one to pair it with.

3 — Mailboxes on a custom domain with IMAP and SMTP and a webmail; aliases, shared mailboxes, filtering and DKIM or DMARC are basic or not described.

5 — Several custom domains with a documented DNS set-up, aliases and distribution lists, shared or functional mailboxes, IMAP and SMTP plus mobile apps, spam and malware filtering, SPF and DKIM signing, mailbox size per plan stated, server-side rules and out-of-office replies.

8 — Exchange ActiveSync or native Outlook (MAPI) support, DMARC reporting and MTA-STS or DANE, catch-all and plus addressing, delegated access and send-as, quarantine an admin can review, send and attachment limits stated, and the deliverability of the outbound infrastructure documented.

10 — A mail platform a large organisation runs on: every protocol above with feature parity stated per client, inbound and outbound gateways configurable, journaling, DANE and MTA-STS enforced, delivery monitoring and bounce analysis for admins, and mail flow documented end to end.

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The Small Firm Owner

Mail on our own domain is documented down to the last DNS record — MX hosts, TXT validation, four DKIM keys as CNAME records, a single SPF record and DMARC with monitoring guidance — plus a catch-all mailbox and aliases on the firm's domain, with IMAP, POP3 and webmail in every tariff and DANE as well as MTA-STS named on the BSI-recommended protocol list. We found no public information on Exchange ActiveSync or native Outlook (MAPI); the help pages describe Outlook via app passwords and a CalDAV plug-in. We also found no public information on shared or functional mailboxes for our kanzlei@ address, on out-of-office rules or on send and attachment limits. 2 8 10 14 15 18

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Calendar, contacts & office apps

How this is scored

What the office plans and writes with: shared and team calendars, free/busy lookup, meeting invitations across providers, room and resource booking, shared address books and a company directory, CalDAV and CardDAV or ActiveSync for phones, Outlook calendar sync, tasks, online office documents with co-editing, file storage that comes with the suite, video meetings and chat inside the bundle, and the desktop and mobile apps.

0 — Mail only, with no calendar or contacts of any kind.

3 — A personal calendar and address book in the webmail; sharing, resources, sync protocols and office apps are basic or not described.

5 — Shared calendars and address books, meeting invitations with free/busy lookup, CalDAV and CardDAV or ActiveSync sync to phones and desktop clients, a company-wide address book, tasks, and either online office documents or a documented integration with an office suite.

8 — Room and resource booking with approval, delegated calendar access, Outlook calendar and contacts sync documented, co-editing of documents and spreadsheets in the browser, file storage with sharing, video meetings in the bundle, and apps for desktop, iOS and Android.

10 — A full office suite that replaces Microsoft 365 for a whole organisation: every function above with Microsoft file formats edited without loss, scheduling across organisations, resource planning, offline editing, an accessible interface stated against a standard, and feature parity across web, desktop and mobile documented.

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The Small Firm Owner

Shared calendars and address books, tasks, browser editing of documents that support common Office formats, a Drive with password-protected sharing and video meetings are all documented, and CalDAV and CardDAV set-up is written out for DAVx⁵, iOS, Thunderbird and Outlook via CalDAV Synchronizer — so the shared calendar would reach every phone in the office. We found no public information on free/busy lookup across providers, room and resource booking for our meeting room, a company-wide address book, or native desktop applications. 3 4 10 16 17

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Security, encryption & compliance archiving

How this is scored

How mail and documents are protected and kept: TLS enforced in transit, encryption at rest, end-to-end encryption or S/MIME and PGP, who at the provider can read a mailbox, two-factor authentication and passkeys, phishing, malware and account-takeover protection, audit-proof archiving that meets GoBD, retention policies and legal hold, eDiscovery, backups and restore of deleted mail, a transparency report on authority requests, and certifications (ISO 27001, BSI C5, SOC 2) with their scope.

0 — No security information of any kind; no encryption, two-factor sign-in or archiving stated.

3 — Encrypted connections and a password login; encryption at rest, two-factor sign-in, archiving and certifications are basic or not described.

5 — TLS in transit and encryption at rest stated, two-factor authentication, spam, phishing and malware protection, restore of deleted mail for a stated period, archiving offered (built in or as an add-on), and a certification such as ISO 27001 stated for the data centres or the service.

8 — End-to-end encryption, S/MIME or PGP supported, GoBD-compliant archiving documented, retention policies and legal hold, enforced two-factor or passkeys for all users, a transparency report on authority requests, and certifications such as ISO 27001 or BSI C5 published with their scope and auditor.

10 — Security that holds up in an audit of a regulated organisation: zero-access or customer-held keys where the provider cannot read mail, eDiscovery, tamper-proof archive with documented verification, every certification published with its report or attestation available, independent security audits or open-source code reviewed, and incident disclosure documented.

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The Small Firm Owner

PGP and S/MIME sit in the webmailer with Mailvelope support and an own key server, two-factor is available in every tariff (though optional), mail is scanned multiple times for malware, a seven-day self-service backup snapshot is stated, and a transparency report is published that even names the share of authority requests rejected, alongside ISO 27001 and BSI C5. But for a tax office the archiving question decides the purchase, and we found no public information on GoBD-compliant archiving, retention policies or legal hold for mail, nor on enforced two-factor for all users. 7 8 9 10 13 18

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Administration, identity & partner management

How this is scored

How an IT team or an IT service provider runs it: an admin console for users, groups, mailboxes and domains, admin roles, single sign-on (SAML or OpenID Connect), sync with Active Directory, Entra ID or LDAP, SCIM provisioning, mobile device policies and remote wipe, audit logs of admin and user actions, usage reports, a documented API for provisioning, multi-tenant or reseller accounts for partners managing several customers, and the support channels and response times per plan.

0 — No administration; one login per mailbox and nothing managed centrally.

3 — A web console to add mailboxes and aliases; roles, single sign-on, directory sync and audit logs are basic or not described.

5 — An admin console for users, groups, mailboxes and domains, admin roles, two-factor sign-in enforceable by the admin, password policies, a documented API or command line for provisioning, an activity or audit log, and business support by phone or ticket stated per plan.

8 — Single sign-on (SAML or OpenID Connect), Active Directory, Entra ID or LDAP sync, SCIM provisioning, mobile device policies with remote wipe, audit logs exportable, delegated administration, partner or reseller accounts that manage several customer organisations, and support response times stated.

10 — Administration that scales across many organisations: every setting reachable by API with parity stated, granular role scopes, policies by group, logs streamed to a SIEM, white-label partner offerings with separate billing, and an SLA with service credits published.

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The Small Firm Owner

A web console manages contract, domains, mailboxes, forwards, passwords and storage, business customers create staff accounts in bulk by CSV, and a documented API is offered for larger environments; support response windows are stated (usually 48 hours Standard, 24 hours Premium) with a 24/7 emergency hotline in the top package. The reseller platform is genuinely partner-grade — create and delete customer accounts, set tariff and mailing-list limits, export invoices as PDF or CSV, keep billing and support in your own name. We found no public information on Active Directory or LDAP sync, SCIM provisioning, mobile device policies with remote wipe, admin roles or exportable audit logs, and single sign-on is offered only as an individual integration without protocol details. 5 6 10 20

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Migration, open standards & exit

How this is scored

How the organisation gets in and out: migration from Exchange, Microsoft 365, Google Workspace or another IMAP provider with a documented tool or service, mail, calendars and contacts carried over, coexistence during a move, standard protocols (IMAP, CalDAV, CardDAV, JMAP, open document formats) rather than proprietary ones, export of a mailbox and of the whole organisation in standard formats (mbox, EML, PST, ICS, vCard), open-source code or a self-hosted edition, what happens to data when the contract ends, and how domains and DNS are handed back.

0 — No way to bring mail in or take it out; a proprietary store with no IMAP access or export.

3 — IMAP access to mail; a migration path, calendar and contacts export and the end-of-contract handling are basic or not described.

5 — A documented migration from Exchange, Microsoft 365 or Google (a tool, an import or a service), mail, calendars and contacts imported, IMAP, CalDAV and CardDAV or ActiveSync access, export of mail, calendars and contacts in standard formats, and the deletion of data after the contract ends stated.

8 — A migration service or tool that moves whole organisations with calendars and permissions, coexistence with free/busy during the move, open document formats supported natively, export of the whole organisation by the admin, an open-source code base or a self-hosted edition, and a data return period after cancellation stated.

10 — An exit that costs nothing but time: every record exportable in open formats with the method documented, a self-hosted open-source edition with feature parity stated, migration in and out documented with the same tools, and a contractual data return and deletion with confirmation.

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The Small Firm Owner

The Audriga move service transfers mail, calendars, contacts and files from a named list of providers including Gmail, Outlook.com and T-Online, a migration assistant sits in the settings, and there is a second-account drag-and-drop path described as running without interruption, plus iCal and vCard import and calendar export to file; thirty days after the contract ends data is irreversibly deleted and users are told to download beforehand. We found no public information on a whole-organisation export by the administrator or a documented migration from Exchange or Microsoft 365, and the migration service is priced as free only for private customers. 6 13 22 23

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European sovereignty

How this is scored

Who the contracting entity and the parent company are, where mailboxes, calendars, contacts, documents and backups are stored and processed, who at the provider or its subprocessors can access them, and who the subprocessors are (data centres, spam filtering, support, payment, AI features). Independently sourced by the sovereignty pipeline. An EU data region offered by a non-EU parent is part of the chain, not the whole of it. A self-hosted or open-source edition the customer runs on its own European servers counts as the customer's chain, whatever the vendor's seat.

0 — Non-EU vendor and contracting entity, hosting unstated, subprocessors unnamed, and no data processing agreement offered.

3 — A privacy policy and a data processing agreement exist, but hosting location is unstated or non-EU and the subprocessors are not listed.

5 — EU hosting available and an EU contracting entity or EU representative, but parts of the chain (spam filtering, support, backups, AI features) run through non-EU providers or a non-EU parent without a stated safeguard.

8 — EU hosting on named infrastructure, EU contracting entity, subprocessors listed with their locations, a data processing agreement published, and security certifications (ISO 27001, BSI C5) stated — or a self-hosted edition documented that keeps every mailbox on the customer's own servers.

10 — Sovereign end to end and evidenced: European ownership, entity, hosting and every subprocessor, or a self-hosted open-source edition with no call home, data export and deletion documented, and certifications published with their scope rather than implied.

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The Small Firm Owner

The imprint names Heinlein Hosting GmbH of Berlin as operator, while the terms name Heinlein Support GmbH for the prepaid service — both Berlin companies — and the business and security pages state that all servers sit exclusively in Berlin on the provider's own infrastructure under German data protection law, with ISO 27001 and BSI C5 stated and a GDPR data processing agreement listed in the Standard and Premium tariffs. The privacy policy names self-hosted Matomo and Conviva via the video player as third-party elements, but we found no public information on a full subprocessor list with their locations, and data centre operators are not named. 1 7 8 10 11 12

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Pricing transparency

How this is scored

Whether a buyer can compute the real annual cost from public pages alone: price per user or mailbox per tier, storage per user, what shared mailboxes, aliases and extra domains cost, which features (archiving, office apps, SSO, advanced security, more storage) cost extra, the first-year discount and the regular price after it, minimum users and term, monthly versus annual billing, and VAT.

0 — No public prices at all; every customer is a sales call.

3 — A starting price per user exists, but how cost scales with storage, users, add-ons or after the first year is unclear.

5 — Tiers are public with their price per user and main inclusions, but at least one commonly needed piece (archiving, extra storage, shared mailboxes, SSO, the price after the introductory period) is unpriced or "on request".

8 — Every tier priced publicly per user with storage, add-ons priced, the regular price after any introductory discount stated, minimum users and term stated, monthly and annual billing compared, and VAT treatment stated.

10 — Complete price computability: annual cost derivable for a given number of users, storage and add-ons, with every support, migration and archive fee and the cancellation and data-return terms published.

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The Small Firm Owner

Three tiers are public at Light 1 €, Standard 4 € and Premium 12 € per month with mail storage of 2, 20 and 50 GB and Drive storage of 0, 10 and 100 GB, extra mail storage quoted at 0,20 € or 0,10 € per GB and extra Drive at 0,40 € or 0,20 € per 5 GB, monthly terms for Standard and Premium, a 30-day trial, and business prices expressly excluding VAT on 14-day invoice terms. We found no introductory discount on the captured pages, so the monthly figures read as the ongoing price — exactly what I need for the second year. We found no public information on minimum user counts, a monthly-versus-annual billing comparison, or the cost of single sign-on and the business migration service. 4 10 13 22

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European sovereignty — proven facts

0 of 6 dimensions proven

Built only from facts shown on the vendor's own pages. A dimension we could not prove is left open, not scored as zero.

Hosting location Not determined ⚠ unverified — uncited Report an error
Hosting options Not determined — uncited Report an error
Open source Not determined — uncited Report an error
Data processing agreement Not determined ⚠ unverified — uncited Report an error
Transfer impact assessment Not determined ⚠ unverified — uncited Report an error

Questions about mailbox.org Business

Is mailbox.org Business European?

Yes. whats-best.ai classifies mailbox.org Business as EU-Made.

Where does mailbox.org Business store data?

The default storage location for customer data is not stated on the vendor’s pages as of 5 Nov 2026. The vendor’s pages mention Germany as hosting location, per the vendor’s page captured 5 Nov 2026.

Does mailbox.org Business have a free plan?

Not stated on the vendor’s pages as of 5 Nov 2026.

What are the best alternatives to mailbox.org Business?

As of 6 Nov 2026, the panel rates grommunio (3.5/5), Infomaniak kSuite (3.5/5) and Nextcloud Hub (Groupware & Office) (3.5/5) highest among the other 14 Business Email & Office Suites products evaluated. Ratings that look equal are rounded to half stars; the order uses the unrounded rating, then the name. The highest-rated European alternative is grommunio (EU-Made). Ratings are the AI panel’s opinion, formed from public evidence: how scores are made. The full list, with European products first: mailbox.org Business alternatives.

Where this could be wrong

What we left out

A claim that does not survive our checks costs us the claim, not the page. This is what was taken off this one.

Do you know more about mailbox.org Business? Tell us Report an error on this page

Sources (23)

The pages every claim on this page was read from — each one checked, dated, and kept verifiable.

  1. 1 Vendor homepage (business) mailbox.org Checked 5 Nov 2026 Details →
  2. 2 Features page (mail) mailbox.org Checked 5 Nov 2026 Details →
  3. 3 Features page (office) mailbox.org Checked 5 Nov 2026 Details →
  4. 4 Features page (drive) mailbox.org Checked 5 Nov 2026 Details →
  5. 5 Features page (admin console) mailbox.org Checked 5 Nov 2026 Details →
  6. 6 Features page (migration) mailbox.org Checked 5 Nov 2026 Details →
  7. 7 Security / trust page mailbox.org Checked 5 Nov 2026 Details →
  8. 8 Security / trust page (certifications) mailbox.org Checked 5 Nov 2026 Details →
  9. 9 Transparency report mailbox.org Checked 5 Nov 2026 Details →
  10. 10 Pricing page mailbox.org Checked 5 Nov 2026 Details →
  11. 11 Legal notice mailbox.org Checked 5 Nov 2026 Details →
  12. 12 Privacy policy mailbox.org Checked 5 Nov 2026 Details →
  13. 13 Terms of service mailbox.org Checked 5 Nov 2026 Details →
  14. 14 Mail, domains & deliverability — found from sitemap kb.mailbox.org Checked 5 Nov 2026 Details →
  15. 15 Mail, domains & deliverability — found from sitemap kb.mailbox.org Checked 5 Nov 2026 Details →
  16. 16 Calendar, contacts & office apps — found from sitemap kb.mailbox.org Checked 5 Nov 2026 Details →
  17. 17 Calendar, contacts & office apps — found from sitemap kb.mailbox.org Checked 5 Nov 2026 Details →
  18. 18 Security, encryption & compliance archiving — found from sitemap kb.mailbox.org Checked 5 Nov 2026 Details →
  19. 19 Security, encryption & compliance archiving — found from sitemap kb.mailbox.org Checked 5 Nov 2026 Details →
  20. 20 Administration, identity & partner management — found from sitemap kb.mailbox.org Checked 5 Nov 2026 Details →
  21. 21 Administration, identity & partner management — found from sitemap kb.mailbox.org Checked 5 Nov 2026 Details →
  22. 22 Migration, open standards & exit — found from sitemap kb.mailbox.org Checked 5 Nov 2026 Details →
  23. 23 Migration, open standards & exit — found from sitemap kb.mailbox.org Checked 5 Nov 2026 Details →