Sequential Responder Upgrade

The requirement is to upgrade an open source sequential autoresponder php script in order to have the functionality of an online autoresponder service with the ability of giving people sequential autoresponder accounts with username and password. The existing script is a single user (only administrator) system - it cannot handle multiple accounts (admin and ordinary users) on the database. As functionality is concerned, apart from the before mentioned point it would also be needed: Wysiwyg html editor (fck editor - [login to view URL]) integration in text area for html messages. - easy peasy :) Integrate a pop-over creating JavaScript page (it is already developed and working just needs to be set with a link, so users can access it) I have into the responders for all users to use. Capability of attachments - able to attach files to messages. Incorporate a click and open email tracker. Integrate an RSS feed as an alternative to sending email to their customers. Integrate a Bad words checker Integrate an Instant-Follow-up option for subscribers to receive the message straight away (Just a simple link to a webpage that contains the follwing article or newsletter. Hard bounces (dead email addresses) removed automatically from the lists. Subscription check and sending emails to a selective part of subscribers + emailing of activity report. Thank you.