How to combine certified email and electronic signature in the same flow (and when to add certified SMS authentication)

From sending to signing: the same evidence flow

In many business processes, electronic signature is just the end of the journey. However, previous communications —such as the request or reminders— are equally important and must also be accredited.

In eEvidence, certified email is not a complement to the signature: it is the channel that makes the entire flow possible with complete traceability, from the initial sending to the final confirmation. Each signature request, each reminder, and each signed document are backed by technically signed and sealed evidence.

Because signing is not enough: you must be able to prove that the signature was correctly requested, sent, and received.

How the combined flow works

A typical communication flow with electronic signature can be structured as follows:

1. Sending the document to sign via certified email (eEvidMail)
   The sender sends the signature request and the associated document. The sending, content, and delivery are certified with legal validity.

2. Electronic signature of the document (eEvidSign)
   The recipient accesses the document through a secure link and performs simple or advanced electronic signature.

3. Optional authentication via certified SMS (eEvidSMS)
   In cases requiring advanced signature, the system sends a digitally signed OTP code to the signer’s mobile number, adding an additional verification layer.

4. Generation of consolidated evidence
   All interactions —sending, access, signature, and authentication— are consolidated into a chain of evidence digitally signed and with a qualified timestamp.

The result: continuous and legally verifiable traceability of the entire process.

Why certified email is essential

Certified email is the first and most important link in the probative chain. Its role is not limited to sending the document: it also certifies each intermediate communication and process closure.

• Guarantees the reliable delivery of the signature request.
• Certifies automatic reminders sent to the signer.
• Accredits the making available of the document even if the user does not sign.
• Provides complete legal coverage, uniting the evidence of sending, delivery, and signature in a single flow.

Without certified email, the signature process begins with a probative gap.

When to add certified SMS authentication

In certain contexts —such as signing employment contracts, financial documents, or sensitive authorizations— an additional level of signer identification is required. This is where certified SMS with OTP comes into play.

With eEvidSMS, each message:

• Is sent and certified with a timestamp.
• Contains a unique verification code (OTP) associated with the signature process.
• Certifies the delivery and access from a verifiable phone number.

In this way, the flow meets the requirements for advanced electronic signature of the eIDAS Regulation, without introducing friction for the user.

Advantages of the integrated flow

• Complete probative traceability: from the signature request to the receipt of the signed document.
• Regulatory compliance: in accordance with Regulation (EU) 910/2014 (eIDAS).
• Legal risk reduction: all communication is certified.
• Smooth experience: familiar channels (email and mobile) without the need for qualified certificates.
• Easy automation: integration via API or use from the eEvidence panel.

Frequently asked questions (FAQ)

Why is it necessary to also certify the signature request?

Because legal validity does not depend only on the act of signing, but also on being able to prove that the document was sent and made available correctly.

When is it advisable to add a certified SMS?

When advanced signature or reinforced authentication of the signer is required, for example, in financial, employment, or informed consent documents.

Can I automate the entire process?

Yes. The eEvidMail, eEvidSign, and eEvidSMS services can be integrated via API to generate fully automated and traceable signature flows.

Conclusion

Certified email is not an accessory to electronic signature: it is its probative foundation. It allows proving that the communication was sent, received, and made available to the signer.

Combined with advanced electronic signature and certified SMS authentication, it offers complete end-to-end traceability, meeting the highest standards of security and legal validity.

At eEvidence, the three channels —eEvidMail, eEvidSign, and eEvidSMS— work together so that every signature begins and ends with legal evidence.