What a placement test sees
- Sends to a rack of test inboxes it owns
- Reports where mail landed for those addresses
- Gmail filters per recipient — a seed inbox has no history with you
- An estimate, extrapolated to your list
Klaviyo counts your opens.
Gmail counts your complaints.
Gmail files complaints where no ESP can see them, so Klaviyo’s column reads zero while your spam rate climbs. SpamSpike reads Google’s own measurement and names the send that moved it.
A seed test estimates. Postmaster is the measurement.
Deliverability tools send to racks of test inboxes and report where those landed. Your subscribers’ Gmail is not that rack.
What SpamSpike reads
- Postmaster: Gmail's own complaint rate on your real mail
- The number Google enforces at 0.10% and 0.30%
- Klaviyo's reporting: every campaign, flow and audience
- Joined read-only. Nothing simulated.
The answer, not another chart.
Hover a spike and the day answers under the chart: the verdict, the mail split, and the senders Google saw.
Named, with labelled confidence.
Three labels, no invented percentage. Timing alone is never printed as a cause.
Exact match
Google’s identifier resolved to one campaign or flow.
Signals agree
Send timing, the audience and the Postmaster curve line up.
Timing only
A send happened near the spike, nothing else connects it. Says so.
Every day opens into its own dossier.
Gmail’s ceiling against Klaviyo’s exact count, the window the day belongs to, and whether it recovered — confirmed by published days, never declared early.
Mark the fix done. The clock starts there.
The after-window opens the day you mark a fix done — never blended into a 90-day average that would bury it. Improved, worse, or too early to say: the product says which.
Questions a buyer actually asks.
How does SpamSpike connect to Klaviyo?
A read-only private API key. No profiles, no message bodies, no write access — aggregate reporting only, revocable in Klaviyo at any time. SpamSpike never sends email.
Does it cover flows as well as campaigns?
Both. Google's flow identifiers are message ids, so matching them against flow ids returns nothing — SpamSpike resolves them through a message index. On one live account: 176 of 239 flow tokens named, and the 63 that resolve to nothing stay labelled unknown.
Is this a placement test?
No. There are no seed lists, no warmup and no scores out of 100. SpamSpike reads Gmail's own complaint measurement from Postmaster and joins it to Klaviyo's reporting.
What about providers besides Gmail?
Gmail is where complaint thresholds are enforced, and Postmaster is the only place its rate is published. Other mailbox providers get health readings from your own Klaviyo delivery data, each judged against its own baseline — never a pretend complaint rate.
How many accounts does one license cover?
Up to 10 Klaviyo accounts and unlimited Postmaster domains. One payment, no subscription.
Who should not buy this?
Senders not on Klaviyo, and anyone shopping for seed-list placement testing or inbox warmup. That is a different category, and SpamSpike does not pretend to be it.