A Cognism export gives you contacts as they looked when the data was last checked. Between that check and your first send, people change roles and companies merge domains. A live check on the export closes that gap, and it costs less than the reputation a bounce spends on a new sending domain.
Many Cognism lists hold European contacts, so the data handling around the check matters as much as the result. The steps below cover both: getting a clean list into your sequencer and keeping the processing tidy for GDPR. For the wider question, see whether email verification is GDPR compliant.
The short version
- A Cognism list, or the CRM view it synced into, that you plan to sequence this week
- A ZapBounce account (100 free checks a month, no card)
The steps
Export only the contacts you'll email
Export the list you plan to sequence in the next week as CSV, from Cognism or from the CRM view it synced into. Keep the CRM record ID column, so results can go back to the right contact.
Set a short retention window
In your ZapBounce account, set the retention on the key you'll use. The default is 30 days, and you can set anything from 0, which deletes the file when you download results, up to 90 days.
Upload the file
Drop the CSV on the bulk page and pick the email column. ZapBounce removes duplicates for free and checks each address with its own SMTP handshake, closing the connection before any message is sent.
Load valid rows into your sequence
Download the results. Every exported column is still there, with
result,reason, theroleanddisposableflags and abilledcolumn added. Filter tovalidand load those rows into your sequencer.Handle catch-all and unknown rows apart
Send
catch_allrows as a small batch from a mailbox you can spare, since their domains accept every address. Holdunknownrows for a day and check them again. Unknowns are never billed.Write the results back to the CRM
Import the file into your CRM matched on the record ID, and mark invalid contacts so the next export leaves them out. The HubSpot and Salesforce pages show the round trip through the API, CSV or Zapier.
Delete the batch when you're done
Delete the job and every address in it with
DELETE /v1/batches/{id}, or let the retention window you set clear it. If a contact later asks to be forgotten,POST /v1/erasureremoves that one address across your account.
Where Cognism exports bounce
Two things turn a good export into a bounce. A mailbox closes after the data provider's last check, which a live check in your send week catches. Or a catch-all domain says yes to everything during checks and rejects the real message later.
Catch-all domains are common in B2B data. About 28% of a 10,000-address B2B benchmark sat on domains that accept every address. ZapBounce labels those rows catch_all and never counts them as valid, so you choose how much sending reputation to put on them.
Keeping the check tidy for GDPR
You confirm a lawful basis to process every address you upload, including contacts from a data provider like Cognism. ZapBounce checks the addresses you hold. It doesn't sell them, doesn't add them to any shared database and never contacts anyone on the list.
ZapBounce is hosted in the United States, and a list leaves that region only for the SMTP probe to the receiving mail server. The data processing terms at /dpa form part of the terms of service and name every sub-processor. A countersigned copy is available on request.
What checking a Cognism export costs
A 1,000-contact export costs $5, 10,000 contacts cost $25, and 50,000 cost $89. Duplicates are charged once, unknowns are never charged, and the credits never expire. Every tier is on the pricing page.
Questions people ask
How do I verify Cognism emails?
Export the Cognism contacts as CSV, upload the file to a verifier that runs a live SMTP check in the week you send, and load only the valid rows into your sequence. Send catch-all rows separately and drop the invalid ones.
Is it GDPR compliant to verify Cognism contacts?
Verification is processing, so you need a lawful basis for every address, as you do for the outreach itself. ZapBounce keeps uploads 30 days by default, lets you set 0 to 90 days per key, and deletes any batch on request.
Why do Cognism emails bounce?
Cognism emails bounce when a mailbox closed after the last data check, or when a catch-all domain accepted the address and rejected the real send. A live check in your send week catches the first, and a catch_all label flags the second.
How much does it cost to verify 10,000 Cognism leads?
At ZapBounce, 10,000 checks cost $25. Duplicates and unknown results are never billed, and credits never expire.