I try to use mu4e with smtpmail to send mail, and use mml-attach-file to add attachment.
If the attachment filename contains non-english name, such as Chinese, the header of message will become Content-Disposition: attachment;
=?us-ascii?Q?filename=3D=22=3D=3Futf-8=3FB=3F5aSN5Lmg5o+Q57qyLTE5LmRvY3g?=, which can show correct filename in mu4e. And there is a utf-8 coding in this header.
But, it cannot be shown in some web mail client such as zoho and gmail and some local client. They display the name by themselves rules such as the mail's subject. And I check the one's header which attachment filename can be shown correctly, it is Content-Disposition: attachment; filename*0*=utf-8''... or filename="=?UTF-8...
The first term of my emacs's coding-system in priority list is utf-8. sendmail-coding-system and mm-coding-system are nil or utf-8, which nil means use the same as emacs configuration.
My language environment is English, and I also tried to set it to UTF-8, but it is no effect.
By the way, my shell variable of LANG is en_US.UTF-8.
Is there a way to make it work correctly?
