Bulk Email Project Consultant

We're looking for someone to take an XML payload and send our email on a dedicated connection. Experience with binding multiple IPs, dealing with mail throttles, and domain keys a definate plus. We already have a mailing program in place but our current program only allows for about 500k a day across 8 smtp servers. We need to get that to at least 1 million a day without compromising deliverability. We currently use Linux smtp servers and Sendmail but we're open to work in Windows, Qmail, or whatever configuration you think will work best.