EU Sovereignty Score
Non-EU vendorTransactional EmailHeadquarters: US

Knock: sovereignty score and 8 European alternatives

Knock is a notification platform for product teams that sends transactional and marketing messages through email, SMS, push, chat, in-app and webhook channels. Developers define workflows and recipient preferences in the Knock service and trigger them through an API and SDKs. The service is delivered as hosted SaaS, so customers install no software. The company publishes its client SDKs on GitHub, while the platform itself is not described as open source.

Knock Labs, Inc. is based in New York, United States. Its data processing addendum covers processing under the GDPR and includes standard contractual clauses for international transfers. The sub-processor list places all named providers in the United States, including Amazon Web Services for hosting, and also names AI model providers. The vendor's materials do not mention an EU data region, so a European organisation should assume that customer data is processed in the US and assess the transfers accordingly.

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Sovereignty score
17 / 1000 = high exposure
100 = sovereign
  • Jurisdiction SOV-210
    Headquartered in the US: CLOUD Act and FISA 702
  • Data residency SOV-30
    No hosting in Europe (US)
  • Cryptographic key sovereignty SOV-320
    Key management with a non-European vendor
  • Freedom from lock-in SOV-640
    Closed source: switching requires data migration
  • Source & runtime sovereignty SOV-4 · SOV-615
    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 11, 2026
HeadquartersUS (US)Verified by hand
EU adequacy decisionOnly for companies individually certified under the EU-US Data Privacy FrameworkVerified by hand
Sovereignty modelVendor-hosted (non-EU)Verified by hand
Data hostingUSVerified by hand
Open-sourceNoVerified by hand
GDPR-compliantYesVendor-stated
CategoryTransactional Email
TypeProduct
Websiteknock.app ↗

How we verify · Something wrong? Suggest a correction

Top EU-based & GDPR-compliant alternatives to Knock

The European alternatives to Knock come from our knowledge base of over 6,200 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

17 European Transactional Email 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 Knock

Knock is headquartered in the United States. US vendors fall under the CLOUD Act and FISA 702: US authorities can compel access to data, even when that data sits in a European data centre. That is the core of the jurisdictional exposure in our model.

Knock hosts data outside the EU (US). Personal data therefore leaves the EU, which requires a transfer mechanism under the GDPR and pulls the data residency score down.

Knock 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 Knock 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 Knock?

It depends on your use case. Strong EU alternatives to Knock include AhaSend, Elastic Email and EmailConnect. On this page you can compare 8 EU alternatives by jurisdiction, data residency and open-source status.

Are there open-source alternatives to Knock?

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

Is Knock GDPR-compliant and where is the data hosted?

Knock is headquartered in US and hosts data in US. The vendor states it is GDPR-compliant, but the data falls under non-EU jurisdiction. For full EU data residency the EU alternatives on this page usually offer more certainty.

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 11, 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

Digital sovereignty in Transactional Email

Transactional Email: Services for sending transactional emails from applications via API or SMTP relay. 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.

Also in this category

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8 European alternatives to Knock — GDPR-compliant & EU-hosted · EU Sovereignty Score