Bulk Emailer Needed

We are launching a new business and have a list of about 500,000 individuals that we need to send an email to for an early-adoption opportunity. These emails are all real and fresh, not from a bought list. I need a reliable bulk emailer to assist me in sending this one-time, plain text email out to this list. You need to already have a system in place that is capable of sending 500,000 emails out in one day. You will also need to be available during US business hours so we can communicate and you can let me know the progress as sending occurs. Please be able to provide reporting to me- I will include my own personal emails as well so that I can monitor and see that the emails were delivered. Please paste this sentence: "I am a bulk emailer that can send your email out to 500,000 addresses in one day and am available during US hours" so that I know you can follow directions and are not a robot.