Why I have lot of "Unverifiable" emails and what I should to do?

Almost always addresses with the "unverifiable" status are so-called "catch-all". As the name says, a catch-all address is meant to catch all email sent to any non-existing email accounts on your domain.

Unfortunally there is no definitive way to determine whether this email is valid or invalid. But statistics says that percentage of catch-alls is directly correlated to the amount of "Invalid" emails. So the more "Invalid" emails you have - the more "Unverifiable" emails will cause bounces.

The best practice for safe sending with "Unveriviable" emails is sending your list in small batches and monitoring which ones causing the highest bounce rates. This will help you to get rid invalid emails from your list.

You can also use another email account to do some catch-all sending in order to save your sending status with your primary email account or sending platform.