my $data = "Goodbye in Japanese is \x{3055}\x{3088}\x{306A}\x{3089}.";

##</code><code>##

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
    ),
);

##</code><code>##

use Net::SMTP;

my $smtp = Net::SMTP->new(
    "localhost",
    Hello => 'localhost.localdomain',
    Timeout => 15,
    Debug => 1,
);
$smtp->mail( $sender );
if ( $smtp->recipient( $recipient ) ) {
    $smtp->data();
    my $msg = $entity->stringify;
    while ( $msg =~ m/([^\r\n]*)(\r\n|\n\r|\r|\n)?/g ) {
        my $line = ( defined($1) ? $1 : "" ) . "\r\n";
        $smtp->datasend( $line );
    }
    if ( $smtp->dataend() ) {
        print( STDERR, "Message sent!\n" );
    } else {
        print( STDERR, "Failure sending data.\n" );
    }
} else {
    print( STDERR, "Rejected recipient.\n" );
}
$smtp->quit();