REST API

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SecuMailer has a REST API for sending secure emails. Both the GDPR and the NTA 7516 functionality are fully accessible via this API.

The API is documented with OpenAPI specification 3.0.1.

The REST API has webhook functionality, which means that the SecuMailer platform can communicate email events with an HTTPS endpoint of the sender.

SMTP API

The SMTP API is usually the simplest integration option for many backend applications because backend applications often have a provision for an SMTP client on board.

We have successfully integrated for customers with Salesforce, SAP and Centric. We have also successfully integrated with patient file systems such as Medisoft Dossier Manager.

GraphQL API

The SecuMailer platform offers insight into email events. This can be done on the basis of a (push) webhook call (see REST API above) and on the basis of a (pull) GraphQL endpoint.

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eIDAS Qualified Registered Email

The smarter alternative to a registered letter: faster, safer, and more cost-effective

Why wait for a registered letter to be delivered when you can send a legally binding, fully compliant message in seconds? With SecuMailer’s eIDAS Qualified Registered Email, you get the same legal status as a registered letter but without paper, postage, or delays.

Instant, secure, EU-wide compliance, and effortless for both sender and recipient.

SecuMailer is the only Dutch qREMS provider on the EU Trusted List.
Delivering the highest level of trust for legally binding registered email, recognised across all EU member states.

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e-IDAS

Legal Certainty

Same legal status as a registered letter, recognised EU-wide.

Save time

Type, send, and deliver instantly, no postal delays.

Cut Costs

Reduce costs by up to 10x compared to physical registered post.

Stay compliant

100% GDPR, NTA 7516, and eIDAS proof. All data stays within the EU.

Why Choose Qualified Registered Email?

When a message needs to hold up in court, standard secure email isn’t enough. eIDAS Qualified Registered Email gives you the legal certainty, speed, and cost savings your organisation needs without compromising privacy or ease of use.

Perfect for legal notices, government decisions, financial statements, contracts, compliance notifications, and any communication where proof of delivery is critical.

How eIDAS registered mail with SecuMailer works

From send to secure in five seamless steps.
Step 1

Write and send

Write your message in your usual email client, such as Outlook, Microsoft 365, or Google Workspace. Simply send it with one click.

Step 2

Qualified timestamp and proof generation

As part of the delivery process, the message is sealed with a qualified electronic timestamp and every step, from sending to delivery to receipt, is logged in a tamper-proof audit trail. This process makes your email legally valid.

Step 3

Recipient authentication

The recipient receives a notification and authenticates their identity. After that, the registered email is delivered directly to their inbox. This ensures the message reaches the right person, securely and verifiably

Step 4

Direct inbox delivery

Once authentication is complete, the email is delivered directly to the recipient’s inbox. Once it’s delivered, the email is removed from our server.

Step 5

Proof of delivery

Both sender and recipient receive confirmation of delivery including proof that holds up in court.

Want more technical detail?

Explore our documentation

Product Features of registered email

  • Email from your own email environment
  • Delivery to the recipient’s mailbox
  • Every email always secure
  • Delivery without portal intermediaries
  • No additional installation or extra software required
  • Works with all email clients
  • Works on all devices
  • Integration with back-office systems possible
  • Delivery receipt available
  • Functional / shared mailboxes possible
  • Custom branding applicable
  • Standard attachment size up to 40MB
  • Send up to 5TB with SecuFiler
  • Integration with any professional mail server
  • Implementation based on existing features
  • Security based on existing features
  • Security based on transport rules
  • API integrations available
  • (Audit) logging available
  • Two-factor authentication based on SMS
  • SAML / SSO available for the management environment
  • GDPR
  • Data minimization
  • ECSO (European Cyber Security Organization)
  • ISO 27001
  • NEN 7510
  • NTA 7516
  • eIDAS
  • ISAE 3000 SOC 2 Type 2
  • Personal service
  • Easily reachable by phone
  • Service commitment: uptime 99.95%
  • Service and support from 9-17
  • Self-service portal
  • Monthly SLA reports

Proven across sectors where every delivery counts

Where legal certainty and privacy matter — SecuMailer delivers.

Municipalities

Municipalities

Deliver official decisions, permits, and tax assessments with confirmed delivery, send responses to appeals securely, and have documented proof they reached the right recipient exactly when it matters.

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Health-Care

Healthcare providers

Send patient records and case files with proof of delivery, transmit test results, lab reports, and X-ray images securely, with the certainty that they’ve reached the intended recipient and verifiable proof for when it matters most.

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Finance

Legal professionals

Serve court summons, rulings, and case files with guaranteed delivery, send contracts or legal notices securely, and maintain irrefutable proof for critical moments.

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Legal

Financial institutions

Provide tax returns, annual statements, and audit reports with verifiable delivery, send regulatory notifications securely, and ensure recipients receive them on time with evidence to prove it.

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business

Business Services

Share signed contracts, service agreements, and NDAs with traceable delivery, send binding offers securely, and have clear evidence they arrived as intended.

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Housing

Housing & Property Management

Send tenancy agreements, rent increase notices, and service charge statements with certified delivery, issue legal notices securely, and know exactly when and to whom they were delivered

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It’s just like registered mail – but it works like email.

Ditch the paper. Send instantly. Stay legally covered.
With eIDAS Qualified Registered Email, you ensure that your critical communications are delivered instantly, securely, and with full legal validity.

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