Harbor Agency (sample)
An agency cleaned client lists in bulk and resolved catch-all M365 domains other tools marked unknown.
3.1Maddresses cleaned
The challenge
Like many teams, Harbor Agency was losing deliverability to invalid and catch-all addresses that slipped past their previous tooling — which marked uncertain results as “valid” and quietly inflated the damage.
The solution
They adopted CorrectInbox for honest, confidence-scored verification. Catch-all Microsoft 365 and Google Workspace domains were resolved where possible, and genuinely ambiguous addresses were returned as “unknown” rather than guessed.
“We finally trust our verification results — including when the answer is ‘we're not sure.’”
The result
The headline number above tells the story — and because we never charge for “unknown” or duplicate results, the cleanup stayed cost-efficient too.