Clean your audience before you import, so Mailchimp's Omnivore filter never pauses your send and you stop losing contacts you paid for.
Clean my Mailchimp list, free Bulk verifier 100 free credits, no card. Pay only for Passed & Failed. Credits never expire.Mailchimp's Omnivore is an automated abuse filter that flags lists with too many invalid addresses, spam traps or bad syntax, and it can block your campaign until you fix it. Mailchimp also auto-cleans (removes) addresses after they hard-bounce, contacts you already paid for. Mailchimp validates format only on import, never whether a mailbox actually exists, so the only durable fix is to verify before you import.
The specific ways an unverified Mailchimp list costs you money and deliverability.
Import an unverified list and Omnivore can flag it and halt the campaign. It is an undisclosed heuristic, so the reliable way to avoid it is to verify first.
Mailchimp marks hard-bounced addresses as "cleaned" and stops sending to them, after the bounce has already hurt your reputation.
On import Mailchimp rejects malformed addresses but accepts syntactically valid yet dead mailboxes, so your audience silently rots.
The accurate, current steps, from export to a clean, safe-to-send list.
Go to Audience, pick the audience, choose Export Audience, then Export as CSV. You receive a ZIP with separate CSVs for subscribed, unsubscribed, non-subscribed and cleaned contacts. Verify the subscribed file.
Run it through Email Verifier API. Mailchimp has no built-in list verification, so this is where invalid, catch-all, spam-trap, role and disposable addresses are caught before they ever reach Omnivore.
Go to Audience, Import contacts, and upload the cleaned file. Mailchimp will not re-add duplicates, bounced or already-unsubscribed addresses it has on record.
For invalid addresses already in your audience, Archive removes them from your audience and your billable count while keeping the record, which is safer than deleting. Never re-add addresses from the cleaned or unsubscribed export files.
What the native option does, and where real verification fills the gap.
| Capability | Mailchimp (native) | Email Verifier API |
|---|---|---|
| Checks if mailbox exists | No (format only on import) | Yes, live SMTP check |
| Prevents the Omnivore warning | No (reactive) | Yes, verify before import |
| Spam-trap & catch-all detection | No | Yes, flagged clearly |
| When it acts | After a bounce ("cleaned") | Before you send |
| Credits expire | n/a | Never |
Cleaning your Mailchimp list, answered.
A "cleaned" contact is one Mailchimp has stopped sending to because it hard-bounced or was flagged as undeliverable. It is effectively removed from your active audience. The catch is that the bounce already happened, which is why verifying before import matters.
Omnivore flags imports with high rates of invalid addresses, spam traps or bad syntax. Mailchimp does not publish the exact threshold, so the dependable fix is to verify your list with Email Verifier API before importing, so the risky addresses are removed first.
Archive removes a contact from your audience and billable count but keeps the record (best for invalid addresses you want off the list). Unsubscribe is an opt-out. Cleaned is a status Mailchimp sets itself for hard-bounced addresses; you do not set it.
Only the format. It rejects malformed addresses but accepts valid-looking ones that do not actually exist, so a clean-looking import can still be full of future bounces.
Pay-as-you-go, one credit per address, billed only for Passed and Failed results, credits never expire, and 100 free credits to start.
Start with 100 free credits, no credit card. See exactly how many of your Mailchimp contacts are about to bounce.
Verify my list free