Email & phone list cleaning
Validate an existing list before you send to it or dial it.
What the problem actually is
Lists decay. Addresses go dead, numbers get reassigned, and a send to a stale list damages sender reputation in a way that is slow and expensive to repair. The same is true of a dialler working numbers that were never allocated.
Signals that carry the weight here
Syntax, MX and — where the provider answers honestly — mailbox existence.
Addresses that were throwaway when captured are certainly dead now.
Numbering plans change; a number valid at capture may not be allocated today.
Where to start
strictness=1 (balanced) — Balanced. For list work, prefer the status and sub_status fields over the verdict — they tell you why to drop a record.
A defensible starting point, not a guarantee. Strictness moves the verdict thresholds only; the risk score itself never changes, so you can re-tune without re-scoring anything.
The call
curl -X POST "https://www.layercall.com/v1/batch" \ -H "X-Api-Key: YOUR_KEY" -H "Content-Type: application/json" \ -d '{"type":"email","items":["a@example.com","b@example.com"]}'
1,000 lookups a month free, no card. Get an API key.
Questions
Is there a bulk endpoint?
Yes. POST /v1/batch takes up to 500 values of one type per request, so you are not looping the single-record endpoints and managing your own concurrency. It bills exactly as 500 single calls — no bulk discount hidden in the plumbing, and no penalty either.