Bulk emailing to my own customers

Marketing wants to send a targeted HTML email to a database of about 14,000 retail clients who have specifically asked to be contacted by email. Since our demographic is young, most of these email addresses are hotmail, yahoo and gmail. These providers all identify this email as junk/spam and send it to the appropriate folder. Even a plain text version is tagged as it mentions prices, “special” etc. Marketing wants to go ahead anyway.
My question is, if Hotmail identifies 6,000 emails from my domain as junk/spam, will they blacklist my domain? Will that get shared with other blacklist servers? Am I just headed for a heap of trouble?

Thanks in advance for you input.