Email::MIME doesn't support Content-Transfer-Encoding: 8bit

[mscha]

If you use :encoding<8bit>, or simply leave the encoding attribute out, and use non-ASCII characters in your body-str, you get an error:

Can not decode a utf-8 buffer as if it were ascii
  in method body-set at /opt/perl6-2018.01/share/perl6/site/sources/CE2F9EE6BB0EA068987D48711B20EC8B84410730 (Email::MIME) line 438
  in method body-str-set at /opt/perl6-2018.01/share/perl6/site/sources/CE2F9EE6BB0EA068987D48711B20EC8B84410730 (Email::MIME) line 496
  in method create at /opt/perl6-2018.01/share/perl6/site/sources/CE2F9EE6BB0EA068987D48711B20EC8B84410730 (Email::MIME) line 102

Quoted printable is so 1990s... And don't get me started on BASE64. 😉
Modern email systems handle 8-bit content just fine.