Set up quickly a php mailer script

I want to create a simple page where i can do bulk mailing. Instead of having a big Email to list, i ll use a big reply-to list and a single email address to wich send all the mails. Please have a look at the draft attached. So as you can see the mailer will have Real time number of emails sent updated, will have the possibility to specify how much times the mail must be sent. if i enter for example 30 000 reply-to addresses and in the form of number to send i specify 30 000. The script will have to send 30 000 emails to the same address but each time with a different and unique reply-to address. The mailer will connect to my smtp details and send mails with plain txt format. I should be able to pause & resume the mailing, and see live how many emails are sent through the smtp. You will have to make sure that the mails go as fastest as possible, for the send rate limit i will set it up in my smtp. I should be able to past a huge list of up to 50 000 mails in the reply-to. You can use any free mailer script out there, i just need to be delivered as soon as possible and with the cheapest price possible. There are already a lot of free solutions out there, you just to do some changes. Failure to deliver the project as needed on time will result on milestone not released.