Deliverability

How to clean your email list (and why it protects your domain)

Cleaning means verifying addresses, removing hard bounces and complainers, pruning long-term non-openers, and de-duplicating. A dirty list bounces, gets complaints, and burns your sender reputation.

26 Apr 2026 6 min readBy Autocloz Editorial, Deliverability team
How to clean your email list (and why it protects your domain)

Short answer: clean an email list by verifying every address (syntax, DNS, SMTP), removing hard bounces and complainers, pruning contacts who haven't engaged in months, and de-duplicating. A dirty list bounces and draws spam complaints — both of which torch your sender reputation and push even your good mail to spam.

The cleaning checklist

  1. Verify — drop invalid + risky (catch-all, role-based) addresses.
  2. Suppress — remove prior hard bounces and complainers permanently.
  3. Prune — cut contacts with no opens/clicks/replies in 3–6 months.
  4. De-dupe — one record per person; merge duplicates.
  5. Re-verify before big sends — lists decay ~2% per month.

Why it's worth it

A smaller, clean list outperforms a bigger dirty one — better placement, higher reply rate, no reputation damage.

Autocloz verifies on import, auto-suppresses bounces/complaints, and surfaces stale segments to prune.

> Start free — verify and clean your list before the first send.

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