Email list cleaning API for cleaner campaigns and imports

List cleaning is more than deleting bounces

"Cleaning" an email list is really three jobs stacked together: removing duplicates, normalizing malformed entries, and stripping addresses that will bounce or harm reputation. A list can be free of hard-invalid addresses and still be dirty — full of the same lead entered twice, disposable-domain signups, and generic role accounts that inflate your count without ever converting.

An email list cleaning API lets you do all three programmatically instead of by hand in a spreadsheet. Verifly runs a live SMTP check on every address and returns not just a deliverable / undeliverable / risky verdict but discrete disposable, role, and catch-all flags. Those flags are what let you build a cleaning policy in code: always drop undeliverable and disposable, drop role for cold outreach, keep catch-all only when the campaign can absorb the uncertainty.

Because it is an API, the same cleaning logic runs every time — on the nightly CRM sync, on the pre-campaign export, and inside an automation node — without a human deciding row by row.

Build a repeatable cleaning policy

1. De-duplicate the raw list and lowercase/trim each address so casing and stray whitespace do not create phantom duplicates.
2. Register at verifly.email/api/v1/autonomous/register for 100 free credits.
3. POST the de-duplicated list to /verify/batch.
4. Apply your policy to the flags: remove undeliverable and disposable always; remove role and catch-all depending on whether the list feeds cold outreach or a trusted transactional flow.
5. Persist the verdict alongside each contact so you can re-clean incrementally instead of re-verifying the whole list next time.

const emails = [...new Set(raw.map(e => e.trim().toLowerCase()))]

const res = await fetch('https://verifly.email/api/v1/verify/batch', {
  method: 'POST',
  headers: { 'Authorization': 'Bearer vf_your_api_key', 'Content-Type': 'application/json' },
  body: JSON.stringify({ emails }),
})
const { results } = await res.json()

const cleaned = results.filter(r =>
  r.result === 'deliverable' && !r.disposable && !r.role
) // keep or drop catch_all per campaign
console.log(`Cleaned list: ${cleaned.length}/${results.length} kept`)