Bulk Emailing Software

I need a mailer software built, either desktop or hosted; whichever works best. It must be able to send 2-4 thousand email a day to C.L. Ad posters... (Hope you know what C.L. means) Must be able to send each mail with its assigned subject, (Provided from the ad posters ad title) Must be able to send at a slow pace and/or varying pace to stay under the radar of C.L. Must have the ability to rotate the "from email address", and or switch SMTP after a certain amount of sent mail. ***Example: after every 5 mails sent, it rotates to another SMTP or it can be set to only send 3 - 8 emails per hour per SMTP account. Must be able to use Gmail SMTP,Yahoo SMTP,MSN SMTP, or any other free SMTP or paid SMTP. Must be able to track opens. ( Not Mandatory) If you have this software already, you can install it on my server, or PC, then you can demo it for me. ****** Please only respond if you can deliver a working solution for this software. Anyway.. waiting for the right person who can implement this task or make the best solution.