A Klaviyo profile carries order history, browsing events and predicted lifetime value alongside the address, which makes the export wide and the decision about what to delete genuinely consequential. Removing a profile discards purchase data your reporting depends on, so verdicts belong in a property rather than in a deletion.
Getting the addresses out of Klaviyo
Lists and segments, choose the list, then Manage list and Export list to CSV. Klaviyo emails the file when it is ready.
Before an import, and again on a schedule for anything the store sync feeds. A one-off pass on an ecommerce account starts rotting the moment the next order lands with a mistyped address at checkout.
What Klaviyo does with the file you bring back
The import rules decide what a re-import actually changes, which is worth knowing before you upload.
The short version
- Klaviyo matches on email and merges into the existing profile, so a re-import updates rather than duplicating.
- Suppressed profiles stay suppressed through an import. Klaviyo will not resurrect a bounced address because a CSV says otherwise, which is correct.
- Custom properties import alongside the address, so a verification verdict can ride along as a profile property and drive segmentation later.
- Active profiles drive billing, so verifying before import keeps the plan tier honest.
The mistake to avoid
Some addresses come back unresolved, and that is a fact about the receiving server rather than a gap in the check. We label those and never bill for them. What that means, and why roughly 28% of business addresses land there, is set out on our page about catch-all domains.
Questions people ask
Should I verify before or after importing into Klaviyo?
Before. Klaviyo bills on active profiles, so importing addresses that will bounce costs money and reputation at the same time.
Can I store the verification result on the profile?
Yes. Import the verdict as a custom property and build segments from it, which lets you hold catch-all addresses back from a first send without deleting them.
What should I do with catch-all results in an ecommerce list?
Keep them and segment them. Business domains with a catch-all configuration are common in B2B, and an ecommerce list heavy in them is usually a wholesale or trade audience worth mailing carefully.