Executive Summary
UnsubCentral needed to activate third-party prospect data at a time when funnel performance was under pressure. Vonazon built a HubSpot-centered process that routed Dun & Bradstreet contacts through ZeroBounce before campaign activation, using validation status to control nurture eligibility, suppress known bad addresses, and separate unusable records from marketing contacts. In the initial campaign reviewed, the source list contained 2,031 contacts, approximately 2,000 entered the HubSpot workflow, more than 1,900 email sends were recorded, and unsubscribes remained below 1%.
Challenge:
UnsubCentral faced declining close rates and low website conversion, establishing a challenging performance baseline.
Solution:
Vonazon routed D&B contacts through HubSpot and ZeroBounce before campaign activation.
Results:
The first campaign processed 2,031 contacts, sent 1,900+ emails, and kept unsubscribes below 1%.
The Challenge
- Declining Sales Performance Close rates had fallen from roughly 20% to about 14%, with website conversion near 0.5%.
- Poor Prospect Data Quality Third-party lists included invalid emails, spam traps, catch-all addresses, and prior hard bounces.
- Deliverability and Cost Risk Bad records could hurt sender reputation while unnecessarily increasing HubSpot marketing-contact costs.
- Weak Funnel Progression UnsubCentral had strong top-of-funnel volume but lacked a disciplined path to move prospects into nurture.
The Solution
Vonazon centered the outbound process in HubSpot and used ZeroBounce as a validation gate between contact acquisition and campaign activation. Dun & Bradstreet contacts entered HubSpot in identifiable imports, and an active list captured newly added D&B records for ZeroBounce processing.
ZeroBounce then populated validation status on the contact record. Vonazon designed the HubSpot workflow so contacts with approved statuses could proceed into nurture, while negative statuses such as known invalid addresses and spam traps were held out of email campaigns. Catch-all addresses were intentionally permitted, which meant the process reduced exposure to known bad addresses but was not designed to eliminate every possible bounce.
Vonazon also created active-list logic to retain visibility into records that should not be mailed. That gave UnsubCentral a way to track poor-quality records from its data source rather than allowing them to disappear from view, and created a basis for reviewing data quality over time.
HubSpot added another safeguard for contacts with existing hard-bounce history. When HubSpot recognized a prior hard bounce, it could prevent the send and populate the hard-bounce reason. Those records could then be captured by the non-marketing contact logic rather than remaining part of the active marketing population.
The marketing-contact decision mattered financially as well as operationally. Records classified as unusable could be marked as non-marketing contacts, helping UnsubCentral avoid paying HubSpot marketing-contact costs for contacts it should not email.
Together, the validation statuses, active lists, workflow enrollment rules, suppression logic, and marketing-contact handling created a repeatable path from third-party data intake to campaign activation. Instead of treating a purchased list as immediately sendable, UnsubCentral could apply a defined quality-control step before outreach.
The Results
The first campaign reviewed against the new process used a source list of 2,031 contacts, with approximately 2,000 contacts shown in the HubSpot workflow and more than 1,900 email sends recorded. The campaign’s unsubscribe rate remained below 1%.
2,031
made up the source list for the first campaign reviewed against the new process.
2,000
contacts appeared in the HubSpot workflow.
1,900+
email sends were recorded for the campaign.
<1%
was the campaign’s unsubscribe rate.
The validation and suppression logic kept known invalid email addresses and spam traps out of the approved sending population. HubSpot also withheld sends to contacts it already recognized as having hard-bounce history, adding another layer of protection before outreach.
ZeroBounce did not eliminate every bounce, nor was that the design. The campaign allowed catch-all addresses to proceed, and the team explicitly expected some of those addresses could bounce. The supported result is therefore narrower and more useful: the process reduced exposure to known bad addresses while preserving an intentional level of reach.
Records identified as unusable could also flow into non-marketing contact handling, preventing clearly unmail-able contacts from unnecessarily contributing to HubSpot marketing-contact costs.
These are operational results rather than evidence of a revenue or pipeline turnaround. They demonstrate that UnsubCentral moved from importing prospect data directly toward outreach to applying a repeatable validation, classification, suppression, and activation process inside HubSpot.
The Impact
Vonazon gave UnsubCentral a more controlled way to activate third-party prospect data in HubSpot.
New records could be validated before nurture, known invalid addresses and spam traps could be suppressed, unusable records could be separated from paid marketing contacts, and campaign teams could test outbound programs against a cleaner, more clearly governed audience.
The result was a safer and more disciplined foundation for outbound campaign execution without overstating downstream revenue impact.
Planning to activate third-party prospect data in HubSpot?
Build validation and suppression into the process before the first send.
