Getting newsletters to Hotmail

We have a newsletter where all users have actively choosen to receive it. We send the newsletter to Danish users only. The problem is that Hotmail often chooses put put our newsletter in the "junk" folder at the user's Hotmail accounts. We are NOT sending spam - there are stright laws against this in Denmark. If someone spam here they will be given a fine on $20 for each spam e-mail sent. What we need is a consultance that can help us getting our e-mails through to the users and not ending up as "SPAM". How do we built the e-mails, how must we send them, are there other techniques etc. Our current mailing system is programmed in PHP using MySQL database. We have programmers so programming skills is not important. Please list your line of experience when bidding for this project. Project will either be paid project based or hourly paid.