Guides & documentation
Everything you need to understand email validation and get the most out of CleanContact — from the concepts to the API.
Guides
What Is Email Validation and Why It Matters
Email validation is the difference between reaching a real person and burning your sender reputation on dead addresses. Here is what it actually checks.
Good, Bad, Unknown: Reading Your Validation Results
Every CleanContact check returns one of three verdicts. Knowing what each means — and what to do with it — keeps your list clean without throwing away good contacts.
How SMTP Mailbox Verification Works
Under the hood, verifying a mailbox means starting a real SMTP conversation and stopping just before you send. Here is the dialogue, step by step.
Catch-All Domains and Why They Are Hard
Some providers accept mail for every possible address, real or not. That breaks naive SMTP checks — so CleanContact takes a different route for them.
Disposable Email Detection: Always-Fresh DEA Blacklists
New throwaway email domains appear every day. CleanContact keeps its disposable-address blacklist current by downloading it automatically from multiple sources.
Cut Bounce Rates and Protect Your Sender Reputation
Deliverability is a reputation game. Validating before you send is the single highest-leverage thing you can do to win it.
Documentation
API Reference: The /validate Endpoint
Everything you need to integrate: the request, the headers, the response shape, and what each status code means.
Authentication & API Keys
How keys work, where to create them, and how to keep public and server-side keys separate and safe.