Internet Message Format

Note

IETF specification defining the Internet Message Format, the syntax of text messages exchanged between users, revising RFC 2822.

Summary

Purpose

IETF RFC 5322 (October 2008) defines the Internet Message Format:

It revises RFC 2822 RFC 5322, Abstract. It covers only the format and part of the semantics of message contents, not their transport envelope RFC 5322, § 1.1. Scope. For eIDAS, only its definition of an email address matters.

Who it applies to

The RFC itself imposes nothing under eIDAS. It applies by reference to providers of person identification data (PID), who ensure that the PID issued to wallets comply with the specifications in the annex to Implementing Regulation 2024/2977 Art. 3(3).

The reference only applies to an optional attribute: the email address (email_address) appears in Table 2 of the annex, among the optional person identification data of natural persons. The table describes it as the address of the user to whom the PID relate, in accordance with RFC 5322 Annex.

Key points

• An optional attribute. The PID provider is not required to include an email address; if it does, the address follows the RFC Annex.
• Selective disclosure. Table 2 groups data subject to selective disclosure, meaning that the user can choose whether or not to show them Annex.
• Two encodings. In the ISO/IEC-mdoc format, the email_address attribute is a text string (tstr); in the SD-JWT VC format, it becomes the email claim, of type string Annex.
• The form of an address. The RFC describes the simple address (addr-spec): a local part, the ”@” character, then an Internet domain RFC 5322, § 3.4.1. Addr-Spec Specification. A mailbox may also carry a display name, the address then being enclosed in angle brackets RFC 5322, § 3.4. Address Specification.
• A caveat in the RFC. The “domain” part is also subject to the rules of other protocols, and the RFC asks implementations to follow the address syntax specific to their context RFC 5322, § 3.4.1. Addr-Spec Specification.

Clauses referred to by the act

• The annex to Implementing Regulation 2024/2977 refers to RFC 5322 as a whole, without a clause number Annex. It does not say which of the RFC’s address forms is to be used.
• The annex to Implementing Regulation 2024/2977 was replaced by Implementing Regulation 2026/1731 Implementing Regulation (EU) 2026/1731; this summary cites the consolidated version that incorporates it.

Links

• Act that makes it applicable: Implementing Regulation 2024/2977 Implementing Regulation (EU) 2024/2977 — consolidated version of 11/08/2026.
• Learning path: step 3, the European wallet.

Written by Asphalia.