use Encode;
use MIME::Entity;

my $entity = MIME::Entity->build(
    Type => "text/plain",
    Charset => "UTF-8",
    Encoding => "quoted-printable",
    Data => Encode::encode( "UTF-8", $data ),
    From => Encode::encode(
        "MIME-Header", $sender
    ),
    To => Encode::encode(
        "MIME-Header", $recipient
    ),
    Subject => Encode::encode(
        "MIME-Header", $subject
    ),
);