gistfile1.txt

use strict;
use warnings;
use utf8;
use Encode;
use Email::MIME::Creator;
use Email::Sender::Simple qw/sendmail/;

sub send {
    my $email = shift;

    my $body = '文字列';

    my $mail = Email::MIME->create(
        header => [
            From => 'noreply@example.com',
            To   => $email,
            Subject => encode('MIME-Header', 'いろはにほへと'),
        ],
        attributes => {
            content_type => 'text/plain',
            charset  => 'utf8',
            encoding => '8bit',
        },
        body_str => $body,
    );

    sendmail($mail, {from => 'noreply@example.com'});
}