Dirty lists waste sends, burn domains, and train reps to ignore CRM. Hygiene is not a one-time scrub; it is a set of gates before every export to sequencing tools.
Dedupe across people and companies
Common failure modes:
- Same person with two emails after a merger
- Shared inboxes captured as “contacts”
- Two records for one buyer after a title change
Pick a single dedupe key per campaign (usually email for email-first, domain + role for account-based). Enforce it before upload.
Validate what affects deliverability
Not every field needs to be perfect. Prioritize:
- Mailbox existence or risk tier for cold email
- Role plausibility (no “info@” as a fake VP)
- Country and language alignment with message and compliance policy
A smaller, validated list almost always beats a large fuzzy export.
Bounce and complaint budgets
Set explicit thresholds:
- Hard bounce rate after first touch
- Spam complaint rate by domain and ESP
When a domain crosses a threshold, pause new volume until you diagnose source lists and copy—not just “warm up” the domain again.
Ownership and audit trail
Someone should own:
- Where the list came from
- Which filter version produced it
- When it was last validated
Without that, debugging a deliverability incident becomes guesswork.
Tie hygiene to downstream metrics
Compare meetings booked per thousand validated contacts versus raw uploads. If the ratio does not improve after hygiene work, the problem is targeting or message, not the scrub.
Clean data makes every downstream step—enrichment, scoring, and personalization—more honest.