106286 Email management

I have a site which gathers information. I was using BigHip to do the double opt-in and auto-send follow up emails. But since they got bought, their system is falling apart and they have no support. I need an email management script/system that requires no technical knowledge. This can be canned, I'm not concerned about it being unique, just easy to use and reliable. It must be able to pop an opt-in window when the user submits the form with the email address on it and once they click "yes", auto-send the first email to them. All emails should be sent in HTML and plain text. Then the system must be able to have a series of emails automatically sent on a timed basis. For example, for this site...I need it to send one email immediately and then one every five days until they cancel or it sends the last email. It must manage the records necessary to prove double opt-in (time, date, ip address of signup, etc.) and if it happened to have information management for the rest of the info gathered (name, address, phone, cell phone, bio, pics, etc.) that's even better. I'm not an overly technical guy, so this really has to be very user-friendly and pretty idiot proof. I also need you to be available for support, if the product isn't working.