WordPress HR Recruiter Directory with sendEmail feature

Hi, I would like to build a word press website similar to the job portal where the job seekers can search the HR / recruiters and can send them email individually or in bulk to many. the site should be like the bulk email service. i have the database of recruiters (name email mobile organisation description) etc. for reference you can visit below link, i want to build / designe something like this [login to view URL] each recruiter box should have individual send message button when user click on sendMessage a small popup window should get open to sent the message to that recruiter. the site should have premium feature. for example the sendMessage for first 20 are free but as user consumes its free credit, he should ask to buy the package 1 email send = 1 credit consumed.