How to clean an email list before a campaign
A practical workflow: export from your ESP, verify CSV, filter invalid addresses, and re-import a clean list.
Sending to a dirty list is the fastest way to raise bounce rate and trigger ESP warnings. If your database grew for months or came from many forms, a meaningful share of addresses has already expired.
Signs your list needs cleaning
- Hard bounce above 2–3% after a campaign.
- Open rate drops without content changes.
- Deliverability warnings in your ESP dashboard.
Five-step workflow
- Export the list from Mailchimp, GetResponse, HubSpot, or CRM.
- Upload CSV to EmailVerifier (extra columns are preserved).
- Bulk verification — live job status in the dashboard.
- Filter — remove invalid and disposable; evaluate risky by strategy.
- Re-import the cleaned list to your ESP.
What teams usually remove
- Invalid — dead domains and non-existent mailboxes.
- Disposable — temp mail and fraud signups.
- Role-based — admin@, office@ (optional, B2B vs B2C).
How often?
Before every major campaign and every 3–6 months for regular sends. After a long pause (2+ months), verification is mandatory.
Automation
Bulk API lets you run cleaning on a cron or webhook — verify new leads before they reach your ESP.