Use case · SimpleVerifier Team
Verifying B2B lead lists
A B2B lead list is only as current as the day its emails were last checked. Verify every export from Apollo, ZoomInfo, Clay or Sales Navigator yourself before it reaches a CRM or sequencer, look up a working address for important rows that fail, and treat catch-all company domains as unconfirmed, whatever label the data vendor gave them.
Lead databases label addresses as verified, likely or guessed, but each label records a check the vendor ran on its own schedule and by its own definition. Contacts move jobs and companies change domains or mail hosts without the vendor's flag changing.
This page is about the data itself: where it goes stale and how to repair it. If you are about to send, the cold email page covers sequencer thresholds and campaign setup.
Where B2B data goes stale
A vendor's 'verified' is a different check, on a different day
Apollo, ZoomInfo and similar tools export their own email status column. Keep it for comparison, but re-check every row, including the ones marked verified. The walkthrough is in verifying an Apollo export.
The company's mail platform decides what can be confirmed
In our Email List Health Report 2026, 46.7% of Google Workspace domains were catch-all against 23.2% of Microsoft 365 domains, and 89.3% of domains whose mail runs through Barracuda. A list of startups on Google Workspace will come back with far more risky rows than a list of Microsoft-hosted firms. That is the domain's behaviour, not a sign the data is bad.
Pattern guesses presented as found addresses
When a tool has no address, some fill the gap with a common pattern such as first.last@. On a domain that rejects unknown recipients, a wrong guess comes back invalid. On a catch-all domain it cannot be confirmed. Common email address patterns explains the formats.
The same person, twice, from two vendors
Merging an Apollo pull with a ZoomInfo list or a Clay table creates duplicates under different addresses. De-duplicate on email before verifying and on name plus company domain before sending, or one prospect gets two first touches.
Turning a raw lead pull into a usable list
Export with the vendor's columns intact
Keep the vendor's own status, the company domain and the person's name. Guides for Apollo, ZoomInfo, Clay and Sales Navigator.
Verify every row, not just the unverified ones
Upload the whole file. You get valid, risky and invalid files back with all original columns, so the vendor's label and ours sit side by side.
Look up a working address for rows that fail
For accounts you care about, run name plus company domain through the email finder or the email permutator, which tests likely formats and stops at the first one the server confirms.
Check whether 'no mail server' means a new domain
When every contact at a company comes back with no mail server, the company has usually moved to a new domain or shut down. Check its website before deleting the account.
Record when you verified
Add a verified_on column before importing into your CRM. A verification is a snapshot, and the date tells the next person whether it is still worth trusting.
What to keep from a B2B export
| Result | What to do | Why |
|---|---|---|
| valid | Keep | The company's server confirmed the mailbox. |
| risky · Accepts all addresses | Keep for priority accounts only | Catch-all domain; the address may or may not exist. Worth a careful one-to-one send for a key account, not a bulk campaign. |
| risky · Role-based address | Keep as an account-level contact | Useful as a company inbox, not as a named prospect. |
| invalid · Mailbox not found | Try the finder, then drop | The person likely left or the pattern was guessed wrong. The finder may locate the right address. |
| invalid · No mail server | Check the company's domain | Often a rebrand or a dead company. Fix the account record, not just the contact. |
Common questions
- Do I need to verify emails that Apollo or ZoomInfo already marked as verified?
- Yes. The vendor's label records its own check on its own schedule. Your check, run in the days before you use the list, reflects whether the mailbox exists now.
- Why does my B2B list come back with so many risky results?
- Mostly because of catch-all domains. In SimpleVerifier's Email List Health Report 2026, 27.5% of 54,463 domains accepted mail for a made-up address, and the rate was 46.7% on Google Workspace. Those addresses cannot be confirmed either way, so they are reported as risky rather than valid.
- Can I find the right address for rows that come back invalid?
- Often. The email finder takes a name and company domain and returns an address the company's server confirmed. It is included in Pro.
- How long does a verification stay accurate on B2B data?
- There is no fixed shelf life, because it depends on how quickly people at those companies change jobs. Re-verify before each use of the list rather than relying on an old result.
Verify a lead export
Pro is $29.99 a month with no cap on verifications: CSV uploads, the API, the Google Sheets add-on and the email finder are all included. Cancel any time.
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