Workflow
B2B database vs email finder: what to verify
A database hands you records someone stored. A finder works out an address from a name and a domain. Both need verification, but they fail differently.
Where each fails
Stored records go stale as people move. Derived addresses fail because the pattern was wrong or the domain accepts everything, which makes the guess look valid when it is not.
What to look at
For database rows, look at the invalid rate by export age. For finder rows, look at the catchall rate: a catch-all domain cannot confirm a derived address, so keep those for a small test batch.