Internet Engineering Task Force (IETF) J. Yao Request for Comments: 6531 W. Mao Obsoletes: 5336 CNNIC Category: Standards Track February 2012 ISSN: 2070-1721 SMTP Extension for Internationalized Email Abstract This document specifies an SMTP extension for transport and delivery of email messages with internationalized email addresses or header information. Status of This Memo This is an Internet S
![RFC 6531: SMTP Extension for Internationalized Email](https://cdn-ak-scissors.b.st-hatena.com/image/square/a6191c61a87f593ad2b55dea2901e4d70ecc9c36/height=288;version=1;width=512/https%3A%2F%2Fstatic.ietf.org%2Fdt%2F12.9.0%2Fietf%2Fimages%2Fietf-logo-card.png)