EU sovereignCybersecurityHeadquarters: DE

mail:u Secure: sovereignty score and 8 European alternatives

mail:u Secure is a server-side email gateway from UPONU GmbH that automates S/MIME and PGP signing and encryption for inbound and outbound mail, so end users can keep their usual client, such as Outlook. A workflow engine applies IF-THEN rules to headers, body and attachments. External recipients without their own encryption read and reply to messages through a web portal. FileLink replaces large attachments with protected download links that have expiry dates and download limits. Outlook add-ins support classification and a pre-send check, and PKI automation requests, renews and validates certificates.

UPONU GmbH is headquartered in Siegen, Germany; its imprint lists two group companies at the same address and no parent company. The solution can run as SaaS in data centres in Germany (according to the vendor), as a private cloud whose location is not stated, or as an on-premise appliance in your own data centre. For European organisations the appliance option means keys and messages stay under their own control. The vendor refers to the GDPR and NIS2 as reference frameworks.

See the 8 European alternatives ↓Assess your stack with mail:u Secure pre-selected

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Sovereignty score

71 / 1000 = high exposure
100 = sovereign

Jurisdiction SOV-2100
Headquartered in the EU: European law applies
Data residency SOV-3100
EU-only hosting
Cryptographic key sovereignty SOV-360
Key management with a European vendor
Freedom from lock-in SOV-640
Closed source: switching requires data migration
Source & runtime sovereignty SOV-4 · SOV-655
Closed source, runtime with the vendor

SOV codes: the matching objective in the European Commission's Cloud Sovereignty Framework. Official source

How the score is calculated

Facts and evidence

Last checked October 14, 2026

Headquarters	DE (EU)Verified by hand
Sovereignty model	Vendor-hosted (EU)Verified by hand
Data hosting	EUVerified by hand
Open-source	NoVerified by hand
GDPR-compliant	YesVendor-stated
Category	Cybersecurity
Type	Product
Website	uponu.com ↗

How we verify · Something wrong? Suggest a correction

Top EU-based & GDPR-compliant alternatives to mail:u Secure

The European alternatives to mail:u Secure come from our knowledge base of over 9,200 vendors. We only list vendors headquartered in the EU or the EEA; fully European-owned vendors rank before vendors with a foreign owner. For each alternative you see the country, the open-source status and a short description.

Score per alternative: 0 = high exposure, 100 = sovereign

198 European Cybersecurity vendors are in the catalogue. View the whole category · Submit an alternative · View category on the map

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Why digital sovereignty matters with mail:u Secure

mail:u Secure is headquartered in DE and therefore falls under European law: the GDPR, NIS2 and the Data Act. No foreign legislation can compel access to your data.

Data is hosted exclusively in the EU, so mail:u Secure scores best on data residency.

mail:u Secure is closed source and hosted by the vendor. The encryption keys and the runtime sit with the vendor and switching requires data migration. Ask about bring-your-own-key, export options and open standards.

What this means for your organisation depends on your whole stack and context. The free assessment weighs mail:u Secure together with your other vendors and gives a total score, a heatmap and the main risk drivers.

Frequently asked questions

What is the best European alternative to mail:u Secure?

It depends on your use case. Strong EU alternatives to mail:u Secure include 1Protection.AI, Actalis and advact. On this page you can compare 8 EU alternatives by jurisdiction, data residency and open-source status.

Are there open-source alternatives to mail:u Secure?

Our list of EU alternatives to mail:u Secure is mostly commercial options. Browse the category on the map for open-source choices.

Is mail:u Secure GDPR-compliant and where is the data hosted?

mail:u Secure is headquartered in DE (EU) and hosts data in EU. That makes mail:u Secure an EU-sovereign choice in its own right; the EU alternatives on this page are comparable European tools.

Details and sources

Verified by handHeadquarters, owner, hosting locations and licence have been checked by us against public sources. Free of charge and for every vendor, not a paid label. Nothing in this knowledge base is taken over automatically. Last checked on October 14, 2026.

Sources

Public sources used in the latest check of this record.

Compliance evidence

The links below point to the vendor's own public documents. We only record what we found: a missing link means "not found publicly", not "not compliant".

No public compliance evidence has been recorded for this vendor yet. Do you know its DPA or subprocessor list? Something wrong? Suggest a correction

Cyber Resilience Act

Public signals that relate to the EU Cyber Resilience Act. They do not count towards the score. A missing line means "not found publicly".

We found none of these signals on the vendor's own site when we checked.

For products in scope of the CRA, CE marking is required from 11 December 2027; this cannot be checked yet.

Checked on October 14, 2026. What is the Cyber Resilience Act?

In the changelog

Earlier changes to this page, as listed in the public changelog.

594 Swiss and German software makers (October 14, 2026)

Digital sovereignty in Cybersecurity

Cybersecurity: Threat detection, endpoint protection, SIEM, vulnerability management. In this category the choice of vendor determines who has legal access to your data, where that data lives and how easily you can switch later.

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