A bad list ruins everything downstream, copy can't fix wrong targets, and bounces will tank your sender reputation in a week. Here's the lead list workflow we use, including the tools and the verification rules.
Where to source B2B lead data
- Apollo, Clay, Ocean.io: firmographic + role data, decent quality
- LinkedIn Sales Navigator: the freshest source; export with care
- BuiltWith, Wappalyzer: technographic enrichment
- Crunchbase, PitchBook: funding triggers
- Specialized vertical databases: often best for niche ICPs
Avoid pre-built "1,000,000 B2B contacts for $99" lists. They're scraped, stale, and full of catch-all addresses that bounce.
The verification stack
Every email must be verified before sending. We layer two verifiers:
- Bulk verification: ZeroBounce, NeverBounce, MillionVerifier
- Real-time verification: right before sending, catches address changes
Discard anything marked risky, catch-all, or unknown. A smaller, cleaner list beats a larger, noisier one, every time.
Hygiene rules we never break
- Maximum 3% bounce rate per campaign, pause if higher
- No catch-all domains in the first 60 days of a new sending domain
- Re-verify any list older than 30 days
- Suppress anyone who has unsubscribed or replied negatively, across all campaigns
- Never re-send to bounced addresses
Building the list, manual signal layer
The best lists combine database pulls with manual signal review. After you pull, spend 30 minutes per 100 contacts checking:
- Is the title still correct? (LinkedIn changes faster than databases)
- Did they tweet/post about your problem space recently?
- Does their company look alive (recent updates, hiring, news)?
This is tedious but compounds. Manually-vetted lists get 2–3× the reply rate of pure database pulls.
List size, smaller than you think
A well-targeted 500-person list will outperform a sloppy 5,000-person list every time. Most of our best campaigns run on 200–800 contacts per segment.
Once your list is right, you need a sharp ICP behind it, see our ICP framework. We handle sourcing, verification and signal review for every client. Want us to do it for you?