Custom Multi-Line Field Email Checker ?

Custom Multi-Line Field Email Checker ?

I see there is on the Marketplace great extensions for both the phone checker and email. Unfortunately neither are a good use-case for how we operate. I am looking to create a custom function (whether this be through Button or Kiosk) where once clicked, that it checks for all the email address listed in that 1 field. 

For our case, We have a record field set up as a Multi-Line Field as "Emails", when the crm user finds more than one email address for the same prospect they are to enter it into here. Once the correct email address is determined and confirmed, then it will be added manually by user to the 'Email' field.

I am hoping someone can help me custom write this, whether the code knows to pull in from that specific field, or whether this is built through Kiosk, for at that time the user can insert the multiple emails for validation. Then of course, we would need a reply screen on what emails are what Status after the check.

Please let me know. I appreciate the help.