Still not able to tell if email is correct

Still not able to tell if email is correct

I am still waiting for the simple ability to tell if the email I entered via a typed form is able to be sent or if it bounces back from the server. This feature is something that I used at Salesforce. I have complaints that a prospect did not get my email and when someone in the company sends the email via Outlook, our Web mail, Yahoo, Gmail, Hotmail, Livemail they get a postmaster alert is is not correct but good ol" Zoho just pretends that life is good and the email went.
PLEASE ADDRESS THIS.. 
IF the email bounces Zoho should let us KNOW>>>>>