I need a bulletproof smtp server

Hello I need a bulletproof smtp setup with trial run of 1000k emails minimum over a period of 3 days to verify the service won't go bad after a few days. The intent is to create a solution that will let us send 500k emails per day minimum. We will need to be able to use the solution before purchasing to make sure it gets delivered and inboxed. A 90% inbox rate needs to be achieved. When the ip adresses go bad. New ones need to be able to be provided. Ofcourse the ip adresses need to be CLEAN and not on a blacklist. We have email verification software in production to make sure our bounces stay low. Kind regards