Before sending any outreach, all email addresses should be verified to prevent bounces and protect sender reputation. Unverified lists — especially those built from old imports or third-party sources — carry significant risk of hard bounces, which can damage deliverability across all campaigns.
Sending to invalid or stale email addresses harms sender reputation with email providers, increasing the likelihood that future messages land in spam. A large database with poor data hygiene (e.g., 40k+ contacts accumulated over years from various list imports) is particularly vulnerable. Verification should be treated as a mandatory gate before any contact enters an outreach sequence.
The approach differs depending on whether contacts are new or already exist in the CRM.
Use Clay's built-in email verification tools during the enrichment and import workflow. Before a new contact is written to HubSpot, Clay can validate the address and flag invalid or risky emails for exclusion.
For contacts already in HubSpot, export the full contact list and run it through Xero Bounce.
Email verification is one step in a broader [1]. In the context of a large, stale database, verification should run in parallel with data enrichment (e.g., correcting industry categorization, updating contact details). The recommended sequence:
| Tool | Use Case |
|---|---|
| Clay | Verification for new contacts during enrichment/import |
| Xero Bounce | Bulk verification of existing CRM contacts |
This process was defined during a sales ops standup between Mark Hope and Jacob Jones while planning a cleanup of a 40k+ contact HubSpot database. The database had accumulated stale contacts from years of ad-hoc list imports, with no prior verification pass. See [3] for full context.