TL;DR
- Apollo verifies emails with its own data network and claims about 91% accuracy, so roughly 1 in 11 "verified" emails can still be wrong.
- Independent estimates put 15-25% of Apollo exports on catch-all domains, where a mail server's "yes" proves nothing.
- Re-verify the CSV before importing it into your sending tool, and handle catch-alls separately.
Why "verified" Apollo emails still bounce
Apollo grades emails using signals from its contributor network, connected inboxes, CRMs and bounce history (how Apollo verifies emails). That's useful, but it's a prediction made at some point in the past, and people change jobs every week. Apollo also argues that independent verifiers are too strict with catch-all domains, which is why the same lead can be "verified" in Apollo and "risky" everywhere else.
Cold emailers on r/coldemail regularly report double-digit invalid rates on Apollo exports marked verified. Apollo only refunds the credit if a verified email bounces when sent from inside Apollo within 30 days. If you send from Instantly or Smartlead, the bounce is yours to absorb.
How to re-verify an Apollo export
- In Apollo, filter to Verified (and optionally Likely to engage) and export to CSV.
- Upload the CSV to MailExchange. Your Apollo columns (name, title, company, LinkedIn) are kept.
- Keep deliverable. Drop undeliverable. Put risky: catch-all into a separate campaign or set it aside.
- Import the clean file into Instantly, Smartlead or your sequencer.
How big is the catch-all problem?
In Hunter's published test, accept-all (catch-all) addresses bounced 27% of the time versus 1% for verified-valid addresses. Hunter suggests keeping catch-alls to a small slice of any campaign. That's why we label catch-alls separately instead of calling them deliverable.