Build a standing 'Never send to fakes' suppression segment

Klaviyo lets every campaign and flow declare both an audience and an exclusion. A standing "Do Not Send" segment backed by Securify's properties is the cleanest way to make hygiene automatic — you set it up once, and every future validation adds new undeliverables to the exclusion pool the moment the properties land.

1. 1

   Create the segment in Klaviyo

   Left sidebar → Audience → Lists & segments → click Create segment (top-right). In the Segment builder, pick Properties about someone → securify_status is one of undeliverable, risky, disposable. Name it "Unsafe — auto-suppressed". The three values cover every address that bounces or is never read. Leave unverifiable and catch_all out — nobody can check those, which is not a reason to stop mailing them.
2. 2

   Attach it as an exclusion to every campaign + flow

   Campaigns → exclude the segment in the audience editor. Flows → Filter → exclude the segment. Set it once, forget about it.
3. 3

   Run Securify on any list you care about

   With Check and tag, every new "unsafe" verdict flows into the segment automatically via Klaviyo's real-time segment engine — no manual re-export, no CSV re-upload. A Check only run adds nobody until you tag it.