Is required under the standard coding of the subject-and in the letters in
Sometimes I receive emails where the subject just in some encoding like in the example below, is it acceptable from the point of view of the standard?
Subject: yew LCA cbyc NBYO
Date: Tue, 29 Nov 2016 05:02:58 -0800
says "Since RFC 2822, conforming message header names and values should be ASCII characters; values that contain non-ASCII data should use the MIME encoded-word syntax (RFC 2047) instead of a literal string"
at the same time as https://tools.ietf.org/html/rfc6532
"However, fullinternationalization 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."