CRM hygiene audit
We found 51.4% of their database was unusable
An automotive service and B2B solutions provider came to us with a database in decay. Outbound campaigns were producing high bounce rates and poor engagement, and their sender reputation was heading toward permanent damage.
The problem
Their outbound sales effort had stopped working. Bounce rates were climbing, engagement was falling, and nobody could say which contacts were still real. The database had been built up over years through imports, trade shows and manual entry, with no verification step at any point. Every campaign they sent was quietly eroding their domain reputation — and because the damage accumulates invisibly, they only noticed once deliverability had already dropped.
Why it mattered
Bounce rates above 10% trigger throttling from most email service providers. Sustained, they lead to domain blacklisting, at which point even legitimate mail stops arriving — including invoices, support replies and mail to existing customers. Meanwhile the sales team was spending roughly half its outbound hours contacting people who had left their companies, in some cases years earlier. The cost was not just the wasted campaigns; it was the slow destruction of an asset that takes months to rebuild.
Our approach
- Syntax & DNS validation — we started with the cheap checks: malformed addresses, invalid domains, and mail servers that no longer resolve. This removed a meaningful share of the list before any deeper work was needed.
- SMTP handshake verification — for every surviving address we opened a connection to the receiving mail server and asked whether the mailbox exists — without sending an email. This is the critical step: it means the audit itself carried no risk to their sender reputation.
- Heuristic decay analysis — valid mailboxes are not the same as current contacts. We cross-referenced role and company signals to estimate which records represented people who had changed jobs, achieving over 98% accuracy on the sample we manually verified.
- CRM-readiness formatting — everything that survived was standardised into a HubSpot-compliant structure — consistent field formats, normalised phone numbers, and clean company naming — so the import needed no manual correction.
Before and after
| Segment | Records | Status | Risk |
|---|---|---|---|
| Syntax invalid | — | Malformed / no DNS | Immediate bounce |
| Mailbox not found | — | SMTP rejected | Hard bounce |
| Role changed | — | Decayed | Soft bounce / no reply |
| Usable | — | Unverified | Unknown |
| Segment | Share | Action taken | Outcome |
|---|---|---|---|
| Unusable identified | 51.4% | Quarantined, not deleted | Reputation protected ✓ |
| Verified & current | 48.6% | Standardised for HubSpot | Import-ready ✓ |
| Decay accuracy | 98%+ | Manually spot-checked | Confirmed ✓ |
The stack
ZeroBounce
Bulk verification and confidence scoring across the full database.
SMTP handshake
Direct mailbox existence checks with no send — zero reputation risk during the audit.
HubSpot
Destination platform. Output formatted to import without manual correction.
Results
“B2B data decays at an annual rate of 25%. We don’t just provide leads — we make sure your CRM stays a working engine rather than an archive of people who used to work there.”
What we handed over
- Full segmentation of the database into usable, decayed and invalid
- Quarantine file — nothing deleted, everything reviewable
- Per-record confidence score from ZeroBounce
- HubSpot-compliant import file for the verified segment
- Written summary of what was found and why
- Recommended re-verification cadence to stop it recurring
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