best way to send bulk

in a previous post I pointed out i had a list of lawyers contacts.

my question now is,
what's best way to email blast a list if the persons on the list didn't opt-in? or better yet, how to get my emails from going directly to the spam box?

You will probably be better off doing a JV with somebody who knows how to mail and inbox or pay for somebody to do it for you
https://www.blackhatworld.com/forums/joint-ventures.65/
https://www.blackhatworld.com/forums/hire-a-freelancer.76/

Answer to your question depends on volume