Email deliverability expert needed

We are a Danish company doing permission based marketing. We have several mailinglists and a total of 250,000 subscribers. This number grows rapidly, and our target is 500,000 within a year. We currently send about 6 million e-mails per month - this number will grow as well. Even though we only send opt-in emails, we are facing the same delivery problems as many other companies. Therefore we are looking for an e-mail marketing expert, who can help us on a long term freelance basis and improve our delivarability rate to major Scandinavian ISP's significantly. The person we are seeking must be an expert in every aspect of improving delivarability. Persons who are able to show proven results only. Please post your experience and a little description on how you will be able to help us in the future. We are willing to invest in new software solutions etc. if needed. Some of the keywords you should master at an expert level: SPF Records/Domain Keys/Feedback Loops/MTAs/ISP Relationships/Bounce Handling/List Management/Avoiding to get caught by Spam Filters etc. PLEASE NOTICE: We do not send spam mails - our lists are all legal opt-in lists. We ARE NOT interested in buying e-mail adresses. WE ARE ONLY INTERESTED IN BIDS FROM SERIOUS E-MAIL MARKETING EXPERTS WHO ARE ABLE TO HELP US SOLVING OUR DELIVERABILITY CHALLENGES NOW AND IN THE FUTURE. ONLY SERIOUS BIDDERS PLEASE