If you are willing to spam everyone, then it will really work.
Ideally, emails should be taken from the people by their choice, and there are many effective ways to collect email addresses from people. You can read this blog by Shortstack for more information.
And if you are still going to follow your technique, it seems obvious that many of your emails will fail to deliver. Sending bulk emails to an extracted email list without email verification
is nothing different than shooting an arrow at a moving target "blindfolded."
I think first, you need to verify those emails before taking any other actions; there are many useful bulk email verification service providers
. You can search it on Google and choose the best one for you.