The Verifier accepts a CSV upload for batch checks. A few habits make the upload work on the first attempt.
- One address per row. Do not put several addresses in one cell separated by semicolons or slashes.
- Give the email column a clear header, such as
email, in the first row. - Save as UTF-8 CSV. Exports from older CRM tools sometimes use a different encoding, which shows up as mangled characters.
- Use commas as the separator. Spreadsheets in some locales default to semicolons, so check the format in the save dialog.
- Trim whitespace and stray quotes around addresses. A leading space makes an otherwise good address unusable.
- Remove obvious non-addresses before uploading: empty rows, placeholder text, and notes that ended up in the email column.
- Dedupe first. The same address twice is the same result twice.
If your file carries extra columns such as name or company, that is fine, keep them so you can match the results back to your own records afterwards.
For files you generate programmatically or on a schedule, skip the upload entirely and use the CLI's bulk verify from CSV or the REST verify endpoint, which fits better into a recurring hygiene job.