// config 設定
$config = Array(
		'charset' => 'ISO-2022-JP',
		'mailtype' => 'text',
		);
 
// library ロード
$this->load->library('email',$config);
 
// encoding 変換
$mail_subject = mb_convert_encoding($mail_subject, "ISO-2022-JP", "UTF-8");
$mail_body = mb_convert_encoding($mail_body, "ISO-2022-JP", "UTF-8");
 
// メール送信
$this->email->from('from@domain.com', 'from name');
$this->email->to('to@domain.com');
$this->email->subject($mail_subject);
$this->email->message($mail_body);
$this->email->send();
 
// DEBUG メッセージ
show_error($this->email->print_debugger());

// Email.php 修正
「system/libraries/Email.php」から stripslashesを削除