What I'm trying to do is to add a replyto field to the core transactional emails of magento. Something like what was archieved in this post with bcc, but for replyTo. Any ideia?
Update: Just to clarify this a little. In the magento TEMPLATE class it is possible to add the replyTo header (core function), but in the MAILER class it is not possible to do that. And that is what I need.
There’s no need to extend any class.
Just use:
$mailTemplate = Mage::getModel('core/email_template');
$mailTemplate->setReplyTo('test@example.com');
$mailTemplate->sendTransactional($templateId, $sender, $recipient, '', $vars, $storeId);