When is sendmail going to support RFC 2047 MIME header encoding?
This is considered to be a MUA issue rather than an MTA issue. Quoth Eric Allman: The primary reason is that the information necessary to do the encoding (that is, 8->7 bit) is unknown to the MTA. In specific, the character set used to encode names in headers is _NOT_ necessarily the same as used to encode the body (which is already encoded in MIME in the charset parameter of the Content-Type: header). Furthermore, it is perfectly reasonable for, say, a Swede to be living and working in Korea, or a Russian living and working in Germany, and want their name to be encoded in their native character set; it could even be that the sender was Japanese, the recipient Russian, and the body encoded in ISO 8859-1. If all I have are 8-bit characters, I can’t choose the charset properly. Similarly, when doing 7->8 bit conversions, I don’t want to throw away this information, as it is necessary for proper presentation to the end user.
