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Business Email & Office Suites

STRATO Mail

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 STRATO GmbH · www.strato.de

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STRATO Mail: AI-assisted analysis on whats-best.ai STRATO Mail: AI-assisted analysis on whats-best.ai (dark)

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.

STRATO Mail at a glance

Vendor
STRATO GmbH
Headquarters
Not stated on the vendor’s pages as of 5 Nov 2026
Data hosting
Not stated on the vendor’s pages as of 5 Nov 2026
Free plan
Yes, per the vendor’s own page source, captured 5 Nov 2026
Panel verdict
The AI panel rates STRATO Mail 2/5, the mean of 6 judges. STRATO Mail is a hosted German business e-mail product — webmail on Open-Xchange, mailboxes on your own.de domain, up to 250 aliases, server-side spam and virus filtering — and the judges' persona-weighted totals cluster at 4.2–4.6. how scores are made
As of
Vendor pages captured 5 Nov 2026; evaluated by the panel 6 Nov 2026. all sources

STRATO Mail alternatives, European ones first →

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

The IT Service Provider

Weighted verdict

Runs a six-person IT service company in Austria that looks after mail for forty client firms, from a two-person architect's office to a hotel group. Spends Mondays on mails that landed in spam and phones that stopped syncing. Wants one partner console for every client, DKIM and DMARC set up without a ticket, migrations it can run itself, support that answers within the hour, and margins it can calculate before it quotes.

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

Scored by The IT Service Provider

Panel median The IT Service Provider 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 IT Service Provider
Mail, domains & deliverability 2 of 5 2 of 5
Calendar, contacts & office apps 1.5 of 5 1.5 of 5
Security, encryption & compliance archiving 3 of 5 3 of 5
Administration, identity & partner management 1.5 of 5 1.5 of 5
Migration, open standards & exit 2 of 5 2 of 5
European sovereignty 3 of 5 2.5 of 5
Pricing transparency 3 of 5 3 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 IT Service Provider

Mailboxes on the client's own domain are documented: up to 250 aliases, 2 GB to 50 GB per mailbox by plan, webmail on Open-Xchange, and server-side spam and virus filtering included in every plan. We found no public information on IMAP, POP3 or SMTP specifics, SPF, DKIM or DMARC set-up, MTA-STS, shared or functional mailboxes, or send and attachment limits — so the deliverability questions my clients ask on Mondays stay open. 1 2 3

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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 IT Service Provider

The webmail is presented as collaboration software based on Open-Xchange, the optional premium mailboxes add external calendar import, a secretary function and real-time sync, and the free move to STRATO carries contacts and appointments. We found no public information on shared calendars, free/busy lookup, CalDAV or CardDAV, room and resource booking, or online office documents and video meetings; the 1 GB online storage in the Business plan is the only file storage shown. 1 2 3

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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 IT Service Provider

Documented are SSL-encrypted mail traffic, two-factor sign-in, spam and virus protection in every plan, and a security architecture certified yearly to ISO 27001 by TÜV, plus an archiving add-on described as GoBD-conform with an IDW PS 880 software attestation. We found no public information on encryption at rest, S/MIME or PGP, a stated restore period for deleted mail, retention policies with legal hold, or a transparency report on authority requests. 3 4 6 8

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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 IT Service Provider

What is documented is online administration of the account, archiving orderable in the customer login, and a service hotline at local rate with an optional paid 24/7 line. We found no public information on admin roles, single sign-on, directory synchronisation, a provisioning API, audit logs, delegated or partner administration for several customers, or stated response times — nothing here supports running forty client firms from one console. 2 4

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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 IT Service Provider

The move in is documented and free, carrying e-mail, contacts and appointments, which is more than a bare protocol pointer. We found no public information on which source systems are covered, coexistence during a move, export of a mailbox or a whole organisation in standard formats, or what happens to the data when the contract ends; the terms shown are a 12-month minimum with automatic renewal and a notice period. 1 2

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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 IT Service Provider

The pages show a German contracting entity, STRATO GmbH in Berlin, with a data protection officer in Berlin, mail 'Hosted in Germany' and 'E-Mail made in Germany TÜV geprüft', a data processing agreement available, and ISO 27001 certification, within a German group (IONOS SE, United Internet). The chain beyond that is undocumented: no named data-centre operator or locations for the mail service and no subprocessor register; the privacy notice states personal data may be transferred outside the EU, and that hashed data goes to marketing services including Meta, LinkedIn, TikTok, Reddit and Google Customer Match. 2 6 7 8

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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 IT Service Provider

Tiers, storage and follow-on prices are public: Basic free for the first month then 2 €/Mon., Mail Plus at 1 €/Mon. for 12 months then 5 €/Mon., set-up 0 €, prices including VAT, on a 12-month minimum term with automatic renewal; the archiving add-on is priced at 2,50 € monthly with 5 GB included and 0,50 € per further GB monthly. The optional premium mailboxes, premium virus scanner and Webmail AI are shown as optional without prices, and the Business plan appears with a first-year saving of 48 € rather than a monthly figure in what we read. Monthly versus annual billing is not compared, so my margin calculation before quoting still has open items. 1 2 3

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

Questions about STRATO Mail

Is STRATO Mail European?

Yes. whats-best.ai classifies STRATO Mail as EU-Made.

Where does STRATO Mail store data?

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

Does STRATO Mail have a free plan?

Yes. STRATO Mail has a free plan, per the vendor’s page captured 5 Nov 2026.

What are the best alternatives to STRATO Mail?

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: STRATO Mail 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.

Sources (8)

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

  1. 1 Vendor homepage (mail, with pricing) www.strato.de Checked 5 Nov 2026 Details →
  2. 2 Features page (own domain address) www.strato.de Checked 5 Nov 2026 Details →
  3. 3 Features page (mail server) www.strato.de Checked 5 Nov 2026 Details →
  4. 4 Features page (email archiving) www.strato.de Checked 5 Nov 2026 Details →
  5. 5 Documentation (help centre) www.strato.de Checked 5 Nov 2026 Details →
  6. 6 Security / trust page www.strato.de Checked 5 Nov 2026 Details →
  7. 7 Legal notice www.strato.de Checked 5 Nov 2026 Details →
  8. 8 Privacy policy www.strato.de Checked 5 Nov 2026 Details →