PEC notification and illegible attachments: burden of proof and presumption of knowledge

1. The fact

   The dispute originates from a taxpayer's opposition to an assessment notice served via Certified Email. According to reports from portals such as Altalex and Cassazione.net, the recipient claimed that, despite receiving the PEC message, the attached document was totally illegible or corrupted, effectively preventing the understanding of the act and the exercise of the right of defense.

   The counterparty produced the complete delivery receipt in court, certifying the transfer of data from the sender's provider to the recipient's provider. The case reached the Court of Cassation, Civil Section, in legitimacy proceedings, to determine whether the mere presence of a delivery receipt was sufficient to complete the notification even in the presence of allegedly unusable digital content.

2. 

   The rules at play

   The regulatory framework is based on three fundamental pillars:

   1. Art. 1335 of the Civil Code establishes the so-called presumption of knowledge, whereby every declaration directed to a person is deemed known when it reaches their address, unless the recipient proves they were unable to have news of it through no fault of their own;
   2. Art. 48 of the Digital Administration Code (CAD) equates PEC transmission to registered mail notification, giving legal value to the date and time of sending and receiving;
   3. Art. 6 of D.P.R. no. 68/2005 defines the function of the delivery receipt, which constitutes legal proof of sending and the delivered content if issued in complete mode. While other profiles regarding address validity are covered in dedicated articles, what matters here is the message's capacity to place the file within the recipient's sphere of accessibility.

3. What the jurisprudence says

   The jurisprudence of legitimacy has clarified that PEC notification is completed for the sender at the time of sending and for the recipient at the time of delivery to their mailbox. The judges specified that the delivery receipt enjoys a presumption iuris tantum of content integrity. A generic complaint of illegibility is not sufficient to overcome this presumption.

   The consolidated orientation imposes a clear reversal of the burden of proof: once the complete receipt is produced, it is the recipient who must demonstrate the existence of an unforeseen and insurmountable technological flaw. The Supreme Court also highlighted how the recipient is burdened by a duty of diligence requiring them to promptly report any technical anomalies found when opening attachments to the sender, rather than raising the flaw only in court.

5. Analysis drafted and verified with edit.legal

   To verify the provisions cited in this article, we used edit.legal. Test our legal AI on official sources and apply it to your own matters.

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8. What it teaches professionals

   1. Always keep server logs and original error messages if intending to contest a PEC notification for technical reasons.
   2. Advise clients to immediately report via PEC to the sender any inability to open an attachment, pre-establishing proof of their good faith.
   3. Remember that the complete delivery receipt is the only document ensuring the enforceability of content against third parties in case of litigation over notification validity.
   4. Avoid exceptions based on mere illegibility if not supported by a solid preventive IT expertise.

References: Art. 1335 c.c.Art. 48 D.Lgs. 82/2005 (CAD)Art. 6 D.P.R. 68/2005Art. 156 c.p.c.

Editorial oversight: Avv. Federico Papa·ICAMUpdated 3 October 2026Content drafted with AI support and subject to editorial source checks. Despite these controls, inaccuracies may remain: reports and rectification requests are welcome. Report a correction