Custom Bulk Email Verifier Program

I need a custom program or software built to verify emails... There are many programs available, but none seem to be able to handle the bulk amount we need. We need to easily be able to verify 5+ million per day. We can run it on a server if necessary..... We had a set-up but our programmer cant get it to do the volume we need. Sample of what we need: We import bulk lists of 1+ million emails. Addresses for email are extracted from a Domain Naming Server (DNS) and email Verifier program tries to connect with SMTP-servers and simulates the sending of a message. It does not send the message though - email Verifier program disconnects as soon as the mail server informs the program whether the address exists or not. Then when finished puts the verified emails in a .csv file. Again, there are many software's out there, we have tried almost all and they can't handle the size of our lists. Please only bid if you completely understand the project and you are able to get this done!