Using VBA to verify if email addresses exist

I have a list of emails in an Excel spreadsheet. I am try to create a VBA macro that will determine if the email recipients in my list ACTUALLY exist WITHOUT actually sending an email. (Note, the sytax of the emails is CORRECT --- I just don't know if the recipents are real people.)

For example: the email address someone@domain.com has correct syntax but how do we tell if "someone" actually exists at domain.com WITHOUT sending an email message to username? And whether domain.com exists.

Thanks