Bulk email list cleaner for large CSV files

How to clean a large list

1. Export your existing contacts from your CRM or email tool as CSV; keep the original file as your backup.
2. Choose the CSV or TXT file on the homepage. Uploads up to 20 MB and 250,000 rows can be archived; verified runs are limited to 1,000 unique retained addresses per action.
3. Select duplicate removal, name formatting and any appropriate disposable or role-inbox filters.
4. If you maintain bounce or unsubscribe records, upload the suppression CSV separately.
5. Click Clean & verify, check the summary counts, inspect the sample rows and download the clean, removed and flagged CSV files.

What counts as a bulk email cleaning problem?

• Duplicate addresses copied from multiple CRMs or campaigns.
• Badly formatted addresses such as missing @ signs or impossible domains.
• Optional exclusions, including known disposable domains, role-based inboxes and bounced or unsubscribed contacts you supply.
• Columns and names needing consistent formatting before you import a CRM list.

What happens with very large files?

• The browser handles the local cleaning work. A 100,000-row file may take longer on an older phone than on a desktop.
• The limit is 20 MB per file and 250,000 rows in this version; split larger exports into smaller files.
• Clean & verify checks eligible mail domains automatically and uses up to one account credit per eligible unique address every run, including repeats.

How to review your results

• Keep the exported clean file and review-flag file separately. A flagged email should not automatically be treated as undeliverable.
• Check your chosen rules before deleting role inboxes: info@ and support@ can be legitimate addresses.
• Verify suppression files are complete and current. Cleaning never gives permission to send marketing to a person.

Frequently asked questions