You should take a look at EmailLabs and Lyris (same company, different solutions that are scalable to different sized lists).

I usually implement one of these solutions at any company I am working with. They are reputable, willing to work with adult and hardcore and they will work with you to get a clean list.

Although, like many other companies, their spam tolerance is 1 in 1000, they are very tolerant of new lists and new companies who keep open lines of communication.

Email Labs is the more enterprise and customizable solution. Lyris has newsletter style marketing options that are very inexpensive to operate and very easy to use.

Mary