Clearbit is a data API that lets you enrich your person and company records with social, demographic, and firmographic data.
You can find more information here.
How this Clearbit + TrueMail integration works
1. Add new record to a Clearbit account
2. Zapier sends the email to be verified with TrueMail
3. Zapier updates the existing Clearbit record with TrueMail result code in a custom field