RFC 6856 · PROPOSED STANDARD · 2013
SUN · 14 JUN 2026
Post Office Protocol Version 3 Support for UTF-8
Overview
RFC 6856, “Post Office Protocol Version 3 Support for UTF-8”, is a Proposed Standard document published in March 2013 by R. Gellens, C. Newman, J. Yao, K. Fujiwara. It obsoletes RFC 5721. The canonical text is published by the RFC Editor.
Abstract
This specification extends the Post Office Protocol version 3 (POP3) to support international strings encoded in UTF-8 in usernames, passwords, mail addresses, message headers, and protocol-level text strings.
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 6856 is hosted at rfc-editor.org. Available in TXT,HTML.
Relationships to other RFCs
Other RFCs from 2013
- RFC 6855 IMAP Support for UTF-8
- RFC 6857 Post-Delivery Message Downgrading for Internationalized Email Messages
- RFC 6854 Update to Internet Message Format to Allow Group Syntax in the "From:" and "Sender:" Header Fields
- RFC 6858 Simplified POP and IMAP Downgrading for Internationalized Email
- RFC 6853 DHCPv6 Redundancy Deployment Considerations
- RFC 6859 Update to RFC 3777 to Clarify Nominating Committee Eligibility of IETF Leadership
- RFC 6852 Affirmation of the Modern Paradigm for Standards
- RFC 6860 Hiding Transit-Only Networks in OSPF