Query number of users matching search criteria &send bulk email to users matching criteria

Hi, I’m trying to make an app to reach out to actors who match certain criteria.

This is the user flow:

  1. I have a list of actors categorized by age and gender
  2. I want to search for a male actor between 40-50 years.

When I press search I would like to see how many actors I have available and then send a bulk email to all of them inviting them for a job.

How would you go about this? Many thanks <3