Internationalized Email Headers
RFC 6532, “Internationalized Email Headers”, is a Proposed Standard document published in February 2012 by A. Yang, S. Steele, N. Freed. It updates RFC 2045. It obsoletes RFC 5335. The canonical text is published by the RFC Editor.
Abstract
Internet mail was originally limited to 7-bit ASCII. MIME added support for the use of 8-bit character sets in body parts, and also defined an encoded-word construct so other character sets could be used in certain header field values. However, full internationalization of electronic mail requires additional enhancements to allow the use of Unicode, including characters outside the ASCII repertoire, in mail addresses as well as direct use of Unicode in header fields like "From:", "To:", and "Subject:", without requiring the use of complex encoded-word constructs. This document specifies an enhancement to the Internet Message Format and to MIME that allows use of Unicode in mail addresses and most header field content.
This specification updates Section 6.4 of RFC 2045 to eliminate the restriction prohibiting the use of non-identity content-transfer- encodings on subtypes of "message/". [STANDARDS-TRACK]
What “Proposed Standard” means
An entry-level standards-track specification: stable, peer-reviewed and a solid basis for implementation, though it may still evolve before becoming an Internet Standard.
The canonical text of RFC 6532 is hosted at rfc-editor.org. Available in TXT,HTML.
- RFC 6531 SMTP Extension for Internationalized Email
- RFC 6533 Internationalized Delivery Status and Disposition Notifications
- RFC 6530 Overview and Framework for Internationalized Email
- RFC 6534 Loss Episode Metrics for IP Performance Metrics
- RFC 6529 Host/Host Protocol for the ARPA Network
- RFC 6535 Dual-Stack Hosts Using "Bump-in-the-Host"
- RFC 6528 Defending against Sequence Number Attacks
- RFC 6536 Network Configuration Protocol Access Control Model