MailStore: on-premises or cloud archiving?

Three operating models, one archive technology

MailStore (MailStore Software GmbH, part of OpenText since December 2019) is an established solution for central email archiving in small and mid-sized businesses. Since October 2025 there have been three routes: MailStore Server for operation in house, MailStore Cloud as a service run by the vendor, and hosted archiving via a service provider based on the MailStore Service Provider Edition (SPE).

MailStore Server: everything in house

MailStore Server runs on a Windows system at your premises; according to the vendor it supports Windows 11 and Windows Server 2016–2025. Operation and responsibility rest with you or with me as the provider looking after the server for you. The software stores complete, faithful copies of emails, with access through the familiar folder structure, full-text search or directly from Outlook. The current version is 26.3 (as of September 2026).

• Full data sovereignty: the archive is physically with you.
• Tamper protection via SHA hash values of the content and internal AES256 encryption; with Legal Hold, emails cannot be deleted regardless of any other settings.
• You take care of the server’s hardware, backup and updates, or outsource exactly that to me. The archive itself needs its own backup, too.
• Licensing: a one-off purchase per user. According to the vendor, the starter pack for up to 5 users costs from 295 EUR plus VAT, including one year of Standard Update & Support Service. The service is available as Standard or Premium with a term of 1, 2 or 3 years (as of September 2026).

MailStore Cloud: run by the vendor

Since 6 October 2025, MailStore has offered its own cloud variant, MailStore Cloud. According to the vendor, OpenText runs it in an ISO-certified data centre in Germany and takes care of hardware, software maintenance and availability. User licences and storage are booked through a web portal, billed monthly and can be increased or reduced with immediate effect. MailStore Cloud is available through partners; the vendor does not publish a list price on its website.

• No server of your own, no maintenance of your own: operation and updates are handled by the vendor.
• Monthly costs instead of a one-off licence, scaling easily as the number of mailboxes grows.
• According to the vendor, there is also an IDW PS 880 software attestation for MailStore Cloud (version 26.3). You should still check data processing terms, export options and notice periods in the contract.

Hosted by a service provider: the Service Provider Edition

With the MailStore Service Provider Edition (SPE), IT service providers run archiving on their own infrastructure and deliver it as a service, from a simple single-server mode to multi-server operation. Each customer gets its own instance, separate from the others, and the provider sets prices and scope. One example of a hosted service based on MailStore is EL mailarchive from ELOVADE, which according to the provider uses data centres in Germany, bills monthly and is sold through partners.

• No server of your own, no maintenance of your own: operation runs at the provider.
• Archiving can be bundled with other services from the same provider.
• Important: clarify where the data is stored, who runs the data centre, which backups are included and how you get your data back if you switch providers.

Which variant fits you?

• MailStore Server if data sovereignty in house is the top priority and you want to run suitable hardware or have it managed.
• MailStore Cloud if you do not want to run a server and prefer operation by the vendor itself in a German data centre.
• A service provider offering if you want archiving together with other services from a single source.
• In every case: prices and contract terms change. I check the current terms for your situation.

If you use Microsoft 365, also read what the built-in tools can do: Exchange Online and the GoBD. How I plan and look after archiving is described on the email archiving page.