Apollo's email status travels with the contact record. When you export a list, you get the label Apollo held on that day. The mailbox behind it may have changed since, because people leave jobs and companies rename or retire domains. A stored label can't age in step with the inbox it describes.
A live check asks the receiving server right now. We run our own SMTP handshake on port 25: we look up the MX record, open the connection, offer the address at RCPT TO and close before DATA. No email is sent. The server's reply, a 250 or a 550, is a fact about that mailbox this week.
Apollo lists lean on corporate domains, and that's where catch-all servers cluster. About 28% of a 10,000-address B2B benchmark sat on domains that accept every address. No verifier can confirm a single mailbox on those domains, so your export needs a check that tells you which addresses sit on them.
The practical move is to verify the export between Apollo and your sequencer. Send valid addresses in your main sequence. Put catch_all addresses in a smaller batch on a mailbox you can spare, and drop every invalid. Our Apollo integration guide walks through the export and the split step by step.
The cost stays small. ZapBounce charges $5 for 1,000 checks and $25 for 10,000, and credits never expire. Unknowns and duplicates are never billed, so a contact saved in two Apollo lists costs you one credit, not two. You can start with 100 free checks a month and no card on the pricing page.
Related questions
Is Apollo's verified status enough before a cold email campaign?
Apollo's verified status is a useful first filter, but it records a check made before your export. Run a live SMTP check on the list in the week you send so it reflects the mailboxes as they stand. At ZapBounce that costs $5 per 1,000 addresses.
How often should I re-verify Apollo contacts?
Re-verify Apollo contacts before each new sequence and whenever a list has sat unused for more than a month. Business addresses change as people change jobs. A fresh check costs one credit, and ZapBounce credits never expire.
Why do Apollo emails bounce when they were marked verified?
Apollo emails marked verified can bounce because the mailbox closed after the check, or because the domain accepted every address during the check and rejected the real send. A live check just before sending catches the first case. A catch_all result flags the second.
Does verifying an Apollo export email my contacts?
No message reaches your contacts. The check stops at the RCPT TO step and closes the connection before any message data is sent, so the person on the other end sees nothing.