Bulk email

What is a good email marketing service that does not require opt-in? Its a list of 38,000. Please save the opt in best practices for someone else. I have been assigned to find this information as part of my job.

Thanks in advance
How I got my list is not the point. it is not an opt-in list. Is there a company that has an email marketing service where I can use a list that is not opt in
For instance I cannot send emails using my list through an email marketing company like constantcontact - because they require my list to be opt-in in order to use there service.
I would also like to send one email to the entire list. So 38,000 emails in one send.

Thanks

I’ve had a few websites for awhile now. I’ve done the yahoo sponsor search, google adwords, and everything else out there. After learning about email marketing I believe I could have my best sucess with this. I’m not trying to sell anything I’m just trying to get people to join my social network website (writers). So what I need to know is how do I get started? Where do I find email lists? What’s that best free program I can use to send bulk emails? I’m not trying to invest any money in this so I need to know free ways to do this (I know about the pay ways). So if anybody knows anything please let me know because I need my website to grow faster.