RFC 6858 · PROPOSED STANDARD · 2013
SUN · 14 JUN 2026
Simplified POP and IMAP Downgrading for Internationalized Email
Overview
RFC 6858, “Simplified POP and IMAP Downgrading for Internationalized Email”, is a Proposed Standard document published in March 2013 by A. Gulbrandsen. It updates RFC 3501. The canonical text is published by the RFC Editor.
Abstract
This document specifies a method for IMAP and POP servers to serve internationalized messages to conventional clients. The specification is simple, easy to implement, and provides only rudimentary results.
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.
Read this RFC
The canonical text of RFC 6858 is hosted at rfc-editor.org. Available in TXT,HTML.
Relationships to other RFCs
Other RFCs from 2013
- RFC 6857 Post-Delivery Message Downgrading for Internationalized Email Messages
- RFC 6859 Update to RFC 3777 to Clarify Nominating Committee Eligibility of IETF Leadership
- RFC 6856 Post Office Protocol Version 3 Support for UTF-8
- RFC 6860 Hiding Transit-Only Networks in OSPF
- RFC 6855 IMAP Support for UTF-8
- RFC 6861 The "create-form" and "edit-form" Link Relations
- RFC 6854 Update to Internet Message Format to Allow Group Syntax in the "From:" and "Sender:" Header Fields
- RFC 6862 Keying and Authentication for Routing Protocols Overview, Threats, and Requirements