You'll get back all your original data as well as both the verified and unverified (pattern matched) email results.
These are the columns with a description of what they contain
Email: Contains both verified emails and unverified emails.
Verified email only: Contains only a single verified email.
Alternate emails: Contains any other verified emails found for that individual. For example, Tim Cook at Apple will have more than one email address. If he has 4 emails then we'll select one and put it in the verified email only column and list all the others here.
Email_type: Tells you what kind of email was found. Verified or Unverified.
Which one should I upload to my email sending tool?
We like to upload the 'verified email only' column when we don't want any bounces.
We like to upload the 'Email' column when we don't mind a few bounces and because every single email matters.