Know if your list will bounce before you hit send.

Pick 20 contacts at random

Take them from the list you're about to send to, spread across the whole list. Don't use the first 20 rows: lists are often sorted, and the top is usually the cleanest part.

Run 5 checks on each contact

A contact fails if it misses any one of these.

1. Email is validRun it through an email verifier. "Valid" passes; invalid fails. Catch-all or unknown doesn't fail, but mark it.
2. Still at the companyTheir LinkedIn profile shows them in that role at that company today.
3. Right roleTheir title matches the buyer you actually sell to, not someone two levels away.
4. Company still fitsThe website is live, and the industry, size and country match your target.
5. Not a duplicateThey aren't already in your CRM, in another sequence, an existing customer or opted out.

Count the failures

Each contact counts once, even if it fails more than one check.

Catch-all or unknown emails aren't bad, just unconfirmed. If more than 5 of your 20 are catch-all or unknown, send those in a smaller, separate batch so a bounce spike can't hurt your main campaign.

These bands are rules of thumb from 15 years of list work.