How to measure email coverage in a contact dataset

Email coverage is the percentage of records in a file that contain a usable email address. A dataset with 1,000,000 records and 310,000 emails has 31% email coverage — it is a contact dataset with some emails, not an email list.

Why it matters

• An email campaign can only reach the records that have an email address. Price per usable email = price ÷ (records × coverage).
• "Contains email" on a product page can mean 3% or 100%. Always look for the measured figure.

How to measure it

1. Open the file in the CSV field analyser (it runs in your browser; nothing is uploaded).
2. Find the email column and read its filled percentage.
3. Check the sample formats: values such as n/a, none, - or a phone number in the email column are not emails.
4. Remove duplicates on the email column with the CSV duplicate checker — coverage after de-duplication is the number that matters.

What counts as a usable email

A usable email has one @, a non-empty local part and a domain with a dot (name@example.co.uk). Coverage does not tell you whether a mailbox exists or whether you may email it.

How DataPackHub reports it

Every dataset page shows Email coverage in its Quick Facts, measured by the inventory scanner from the files for sale, or "Not included" when the dataset has no email addresses. The email lists page only lists datasets where at least 10% of records have an email.

Before you send

Email marketing to individuals often needs prior consent, and every campaign needs an unsubscribe route and a suppression list. Read the compliance page and the dataset's permitted-use statement first.