Bulk Emailing for Webinar

I would like to promote an upcoming conference that I am having in July. I would like to send an advertisement via email to my list of approxiamtely 16 thousand. I need them delivered into the inbox and statistics on how many emails have been opened. My target group is doctors and chiropractors. If you have access to additional emails for this group or suggestions on how to reach this group that would be a plus that I would be willing to pay for.