I'm working on a class, what will be able to send e-mails for our customers.  I need to help with review of my classes design. I'm trying to do it to be easy extendable in future. I'm thinking about using dependency injection to inject InputReaderInterface. But is it worth doing it?InputReaderInterface - has method: getContent()WebReader - for reading source e-mail HTML (implements InputReaderInterface)ParamSetter - for setting different params for users (implements InputReaderInterface)$smtp - class for saving access attributes for SMTPMailer - uses PHPMailer class for sending e-mailsIn the future, params will be loaded from the database.<?php$reader1 = new WebReader($mailUrl);$message = $reader1->getContent();$params = array(  test@test.com => array(    customer => Name Surname  ));$reader2 = new ParamSetter($message, $params);$mailer = new Mailer($smtp, $from, $alias);foreach($rows as $row) {  $reader2->setParamsFor($row[email]);  $message = $reader2->getContent();  $mailer->sendMail($row[email], $subject, $message);}?>
PHP e-mail sending class design
php;object oriented;design patterns;email