v18.6.0
* :issue:`1776` via :pr:`1851`: Add support for UTF-8 encoded attachment file names in ``Content-Disposition`` header via :rfc:`6266#appendix-D`.
* :issue:`1776` via :pr:`1851`: Add support for UTF-8 encoded attachment file names in ``Content-Disposition`` header via :rfc:`6266#appendix-D`.