Do not bother with this tool. There's a reason it's still here on AS indefinitely. It's never worked correctly. Fails at every step like:
Upload file -- fails.
If file does get uploaded, output is horribly wrong. Compare it to any other email list validator and you'll see.

They don't care about the product. No updates in years.

Unfortunately, I can't get refund at this point but had max stacked it. Wish I didn't. Completely trash.