Klaviyo
Three silent send failures on Klaviyo.
Three silent stops the community reports most often on Klaviyo. The shape is consistent: the platform keeps reporting healthy because the failure mode is a legal state, not an error.
Three silent stops the community reports most often on Klaviyo. The shape is consistent: the platform keeps reporting healthy because the failure mode is a legal state, not an error.
Klaviyo
A silent send failure follows the same six steps on every ESP. The platform handles the first two well. The next four are where the lag lives, and where the wallet card flips the timeline.
Klaviyo
The flow sits in Live state. The dashboard shows zero new entries. The trigger metric still exists in the metric library, but someone renamed its event name in the integration upstream, so events arrive under a new name that the flow no longer matches.
This is a contract problem between two systems. The trigger metric is a named contract the integration is meant to honour, and a rename breaks the contract silently because nothing on either side validates the wire-up. Klaviyo holds up its end and waits patiently, so the dashboard reads Live until a monthly report or a customer complaint surfaces the gap.
The Morning send arrival window closed without a matching email.
Monitor live sends to a seed address subscribed to the flow. If the trigger fires reliably in real life, a working flow will land in the seed inbox within minutes. If the seed inbox goes silent for the flow's normal arrival window, the flow is silently broken.
Klaviyo
A flow has multiple email steps in close succession. Smart Sending is enabled at the account level. A subset of the audience hits the guardrail and the second email is suppressed for them. Klaviyo logs it as a Smart Sending skip, not a failure.
This is a guardrail problem. Smart Sending is a platform safety rail doing exactly what it is configured to do, so the skip is logged as a healthy outcome rather than an exception. There is no aggregate signal because, from the platform's point of view, nothing went wrong, and the flow dashboard reads green while a meaningful slice of the audience never received the second message.
Seed each step independently. If the seed for step two stops landing while step one keeps landing, the issue is suppression at step two, not flow health overall.
Klaviyo
The flow filter references a custom property such as customer_tier or signup_source. Someone updated the property key in a CDP or in a CSV import, so the property name still exists on new profiles but the old value is no longer set. The filter starts excluding the bulk of the live audience.
This is a property-management problem. Profile properties are owned by whoever wrote them last, which is usually an upstream system that has no idea which flow filters depend on the values. When the property reshapes, the flow filter still parses cleanly, so Klaviyo treats the resulting empty audience as a legal state and the dashboard offers no link back to the upstream change.
Seed addresses written with the expected property values catch this within one trigger cycle. If the seed inbox dries up while live opens hold steady on older flows, the filter is the culprit.
Klaviyo
Run this against your own programme. If you finish with three or more unticked, the case for instrumenting one flow this week is the rest of this document.
The Detection Guarantee covers your first 90 days on Starter. If we miss a silent send failure on a monitored flow inside that window, we credit up to three months of the affected tier. One page of terms, plain English, no carve-outs.