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Archive · Comparison

MailStore and Conbool Archive compared.

MailStore is an established standard for email archiving. If you need audit-proof archiving with EU data sovereignty and integrated encryption, the differences are worth a direct look. This page compares publicly verifiable points, as of July 2026.

Request a demoArchive in detailAs of: July 2026

In three sentences

What matters.

MailStore is a focused, mature archiving product with a large installed base, part of OpenText since 2020. Conbool Archive is an audit-proof email archive from Germany and part of an integrated suite with MailGuard, SecureMail, SecureFiles, Disclaimer and DMARC. The difference is less in the archive core than around it: EU data sovereignty with a German contracting party, cleartext search over S/MIME and PGP mail decrypted in the gateway, and cloud as well as on-premises from a single codebase.

The five most common questions in a direct comparison.

Statements about MailStore reference public sources; every Conbool claim is verifiable in a demo.

Where is my data and who is the contracting party?

Conbool Archive

The contracting party and data processor is Conbool GmbH in Germany. Cloud operation runs exclusively in EU data centers on ISO-27001-certified infrastructure; alternatively you run the identical product fully on-premises. The data location is named in the DPA.

MailStoreMailStore

MailStore Server is self-hosted, so the data resides in your own environment. MailStore Cloud and the Service Provider Edition are operated via partners. MailStore has been part of OpenText, a group headquartered in Canada, since 2020.

Source: MailStore product pages (Server, Cloud, Service Provider Edition) and the 2020 OpenText acquisition, publicly available. Please confirm the data location for your specific deployment.

Why this matters: For GDPR records of processing, NIS-2 and critical-infrastructure assessments, the provider's corporate ownership (CLOUD Act) matters alongside the physical location. On-premises operation resolves the location question but shifts operations and WORM storage to you.

Focused product or integrated suite?

Conbool Archive

Archive is part of a stack: the same console runs MailGuard (inbound protection), SecureMail (encryption), SecureFiles (large file transfer), Disclaimer and DMARC. One contracting party, one admin portal, one audit log. Archiving captures natively from the gateway mail flow.

MailStoreMailStore

MailStore deliberately focuses on archiving and has done so very well for many years. Encryption, inbound security or signatures are not part of the product and are covered by other vendors when needed.

Source: MailStore product overview, public. MailStore positions itself as a specialized archiving product.

Why this matters: A focused product is strong in its discipline but creates more contracts, consoles and audit layers if you also need encryption and inbound protection. A suite consolidates that, at the cost of a broader scope.

Are encrypted messages searchable too?

Conbool Archive

S/MIME and PGP messages that the Conbool gateway decrypts (SecureMail is part of the suite) are additionally archived in searchable cleartext. The encrypted original stays unchanged in the mailbox. Without gateway decryption, the message is stored as ciphertext and is not findable in full-text search, as in any archive.

MailStoreMailStore

MailStore archives messages the way it retrieves them from the mailbox or journal. Encrypted content stays encrypted unless it is already available decrypted beforehand.

Source: MailStore archiving documentation. MailStore does not include its own S/MIME/PGP decryption layer.

Why this matters: In regulated industries with heavy S/MIME or PGP traffic, searchability decides the practicality of an eDiscovery. The benefit applies only to mail the gateway decrypts.

How do messages get into the archive?

Conbool Archive

Two paths: the native gateway tap captures every message directly in the mail flow, and journaling receives Exchange/M365 journal reports at a dedicated ingestion address (multiple sources per tenant, each with its own sender allowlist). Journaling also captures purely internal mail. Legacy data is imported as PST, MBOX and EML.

MailStoreMailStore

MailStore offers a broad set of retrieval methods: journaling, direct mailbox retrieval via IMAP, Exchange and Microsoft 365, plus file system, PST and EML import as well as an Outlook add-in for search. Retrieval is a core strength of the product.

Source: MailStore Server product page, archiving methods section, public.

Why this matters: Both cover journaling and file import. MailStore's mailbox retrieval (IMAP/Exchange) is broader; Conbool's gateway tap is more tightly coupled to the live mail flow and complements journaling with internal mail.

What about certification and maturity?

Conbool Archive

Conbool Archive is designed for audit-proof, GoBD-compliant retention under German commercial and tax law: WORM with object lock in the compliance tier, an externally anchored hash chain, an automated deletion concept, and eDiscovery with dual control. An IDW PS 880 audit is in preparation.

MailStoreMailStore

MailStore is well established in the market, holds a software certification under IDW PS 880 and offers a DATEV integration. For tax advisors and law firms, that is a strong trust anchor.

Source: MailStore website (IDW PS 880 certification, DATEV partnership), public.

Why this matters: In fairness, MailStore leads here on formal certification and DATEV proximity. If an IDW PS 880 attestation is mandatory today, that is a point for MailStore; if EU sovereignty and suite consolidation outweigh it, for Conbool.

Migration checklist

What a switch from MailStore concretely involves.

A MailStore switch runs as a parallel migration in five steps. The archive is exported and adopted before MailStore is shut down.

  1. 1. Review MailStore scope and contract

    Capture mailbox count, archive size, the retrieval methods in use (journaling, IMAP, Exchange) and the license/maintenance term. This determines import effort and the point at which double costs can be avoided.

  2. 2. Export the MailStore archive

    Export the existing archive from MailStore as EML or PST. MailStore provides an export wizard for this. This export is the basis for the legacy import into Conbool so the history is preserved.

  3. 3. Point journaling at Conbool

    Create a journal source in Conbool Archive and set the Exchange/M365 journal rule to the new ingestion address. From this point new mail flows into Conbool while MailStore keeps running during the transition.

  4. 4. Import legacy data and verify in parallel

    Ingest the EML/PST export server-side into Conbool. Retention periods are calculated from each message's send date. In this phase, verify search, completeness and periods on a representative sample.

  5. 5. Decommission MailStore in a controlled way

    Once new mail runs through Conbool and the legacy data is fully imported and verified, MailStore is decommissioned in a controlled manner. Respect retention obligations during the transition and end the license on time.

These steps are an experience grid and do not replace individual migration advice. We adapt scope and order to your setup in a consultation.

Decision aid

When Conbool Archive, when MailStore.

Conbool Archive fits when …

  • you must document EU data sovereignty with a German contracting party and want cloud or on-premises from one codebase.
  • you want to consolidate archiving, inbound protection, encryption and signatures in one suite instead of running several vendors.
  • heavy S/MIME or PGP traffic should be searchable in cleartext (for gateway-decrypted mail).
  • you want to capture internal mailbox-to-mailbox mail completely (via journaling) and need modern eDiscovery with dual control.

MailStore fits when …

  • you require an archive certified under IDW PS 880 today as a mandatory requirement.
  • the DATEV integration is central to your tax-advisory or law-firm processes.
  • you want a pure on-premises archive without further suite modules and make broad use of mailbox retrieval via IMAP/Exchange.
  • a very large, long-proven installed base is an award criterion for you.

Related

Conbool Archive by industry and use case.

E-Mail-Archivierung für Microsoft 365

Exchange Online und On-Premise über eine Journalregel an eine dedizierte Ingestion-Adresse anbinden.

Learn more

GoBD-konforme E-Mail-Archivierung

Revisionssicher nach HGB und AO, mit automatisiertem Löschkonzept und Hash-Ketten-Audit.

Learn more

Für Steuerberater und Kanzleien

Aufbewahrungspflichten nach § 147 AO erfüllen, Mandantenkommunikation revisionssicher ablegen.

Learn more

Also relevant

Archiving in the wider context.

Email archiving is often weighed together with M365 integration, GoBD compliance and email security. Here are the relevant pages.

Frequently asked questions

See Conbool Archive in your own setup.

A 30-minute demo. Audit-proof archiving with EU hosting, cleartext search of encrypted mail and an integrated suite.

Request a demoArchive in detail

Sources and fairness note

Statements about MailStore on this page are based solely on publicly available sources: MailStore product pages (Server, Cloud, Service Provider Edition), MailStore documentation, the publicly communicated IDW PS 880 certification and DATEV partnership, and the publicly announced 2020 acquisition by OpenText. MailStore is a recognized, mature product; claims not publicly documented are avoided. Statements about Conbool are based on its own product documentation and infrastructure certifications.

As of: July 2026. For your final decision we recommend asking both vendors directly about the points relevant to you and having statements confirmed in writing.

MailStore is a trademark of MailStore Software GmbH or the OpenText group. Conbool is a trademark of Conbool GmbH. This page is an editorial comparison, not official MailStore material.