Mail tracker feature

Hi Guys, Getting feedback from candidates and clients is a nightmare now. Please think about mail tracking tool which is not a big deal, to be integrated to your mail service. It will make our lives much easier. No need to think or they read my mail or not. I just know that:)I'm using gmail utilita now, but if send mail from zoho, it doesn't work. So please think about this. Wish all the best to all great team!