Bulk Verify Email Addresses

Written by Jie Yeu Teoh · Marketing

Updated August 12, 2026

💡 Quick Answer

To bulk verify emails, go to Email Verification in your dashboard, upload a CSV of email addresses, map your columns, and run the batch. Results appear for every email with a deliverability status and score.

If you're sitting on a large contact list, whether from an event, a lead gen form, or an old spreadsheet, checking each email one by one isn't practical. Bulk verification lets you upload a CSV and validate many email addresses in a single run.

How to Bulk Verify a CSV of Email Addresses

Log in to your One Good Card dashboard.
Go to Email Verification.
Under 'Bulk verify email addresses', download the CSV template and fill it up.
Upload your CSV file by selecting it from your device.
The bulk verification will automatically begin.

Reviewing Your Bulk Results

Once the batch finishes, you'll see a results table showing every email address alongside its status:

Deliverable
Risky
Undeliverable
Unknown

Each result also includes a deliverability score and the specific checks it passed or failed, so you can see exactly why an address was flagged.

How to Export Bulk Verification Results

Once verification is complete, click History.
Select the emails you would like to export as the file format.
The file will download with every email address, its status, deliverability score, and validation details.

Use this exported file to update your contact list, remove undeliverable addresses, or import clean data into another tool.

Verifying Contacts Already in Your CRM

If your email list already exists as contacts in One Good Card, you don't need to export and re-upload a CSV. You can sync contacts directly from your Contact Manager and verify them from there, keeping results attached to each contact record automatically.

✨ Pro Tips:

Clean your CSV before uploading. Remove duplicate rows and make sure the email column is clearly labelled so column mapping is quick.
Run bulk verification on old or purchased lists before your first outreach. This is where you'll usually see the highest number of Undeliverable results.
Export your results and filter out Undeliverable addresses before importing the list back into your CRM or email tool.
For contacts already in your CRM, verify from the Contact Manager instead of a CSV so results stay linked to the contact record.

Frequently asked questions

Is there a limit to how many emails I can verify in one batch?

Each CSV upload supports a maximum of 100 email addresses.

What happens if my list has more than 100 emails?

Split your list into separate CSV files of 100 emails or fewer and upload them one at a time.

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