72816 PHP reminder feature

I need a reminder feature, based on PHP/MySQL. Here's how it needs to work: 1) user subscribe with their email (similar to newsletter) 2) reminder MUST be recurring, and the user has the option to decide the time period, for example, receive a reminder email every 1-day, or every one month, or every 5 days and things like that 3) every reminder email sent must have the option for the user to UNSUBSCRIBE 4) users DO NOT have to create account/pass, like I said, it's similar to newsletter, they just write their email address in a form and they are subscribed, NO ACCOUNT, NO PASS, if they want to unsubscribe, they just click on an UNSUBSCRIBE link in the reminder email(again just like newsletter) so user sign up, type in their email address, choose a recurring period of time to be reminded and that's it. It can be a modified open source script(NO PERL-CGI PLEASE), I don't have to own the copyrights. Budget is $60 for this, the first bid showing a live demo will be awarded(please set the option to be reminded every X-number of hours)