How it works
Paste your list, confirm which columns are email and personalization fields, then run checks. The output is a short summary plus a row-level findings table you can export as a CSV.
Paste your list
Paste CSV or spreadsheet rows. The tool auto-detects whether the first row is headers.
This grid shows an example in gray. Paste your CSV or spreadsheet over it.Columns can be in any order. In Step 2, map which column is Email, First name, Company, Domain, and LinkedIn URL. Extra columns are fine.
0 detected rowsNo header row detected
Confirm column mapping
If your export uses different headers, point the checker at the right columns.
Don’t worry about the header names. Just pick the columns that match each field.
Paste rows to map columns.
Detected email and personalization fields will appear here for review.
Run checks
Get a summary and a row-level findings table you can export.
No rows to check yet
Paste rows in Step 1, then run checks to preview issues here.
What it checks
It catches the structural mistakes that break personalization and create duplicate contacts when you import into Apollo, Instantly, Smartlead, Clay, Lemlist, Mailshake, HubSpot, or any mail merge. If you still need candidate addresses first, use the bulk email permutator.
- Flags missing first_name and company columns
- Catches duplicate emails and duplicate domains
- Catches invalid email syntax, role-based addresses, and free-mail domains
- Finds broken LinkedIn URLs and malformed domain formats
- Flags whitespace, non-ASCII characters, all-caps company names, and placeholder values like N/A
How to fix the file before import
The report is most useful when you treat each finding as an import decision. Some rows need correction, some need suppression, and some need a separate research pass before they belong in a campaign.
Missing first name
Look up the name or add a fallback greeting rule in the sending platform.
Role-based address
Move it into a review list unless the campaign is meant for shared inboxes.
Duplicate email
Keep one row so one person does not receive the same sequence twice.
Free-mail address
Check context. It may fit freelancers or small businesses, but weakens company-account outreach.
Placeholder value
Replace or remove it before previewing the merge.
After cleanup, preview the actual message with the mail merge preview tool. A CSV can pass field hygiene checks and still produce awkward merged sentences.
What it does not do
It checks the rows in the CSV you paste: format, obvious typos, duplicates, and merge-field readiness. It does not verify mailboxes, check deliverability, enrich missing fields, score senders, or sync to your CRM. Treat the output as a hygiene pass on this file, not a list quality score.
Privacy
The checks run locally in your browser. If you download a findings CSV, it's generated on your device.