Bounced emails plotted over time, hard and soft together. The shape of this line is an early read on list hygiene and sender reputation, well before deliverability visibly drops.
At a glance
The time-series of bounced emails across the selected period, combining hard bounces (permanent failures such as an address that does not exist) and soft bounces (temporary failures such as a full mailbox or a transient server issue). A bounce is a message Klaviyo attempted to deliver but the receiving server rejected, which is distinct from a dropped email that was never attempted. The value of a trend line, rather than a single rate, is that it shows direction: a slowly climbing bounce line is one of the earliest signs of a degrading list or souring sender reputation, often visible before delivery rate or engagement falls. Use this card to read the trajectory, the bounce-rate card for the proportion, and the bounce-spike alert for sudden jumps. A creeping rise warrants list hygiene; a sharp jump warrants an immediate reputation check.
| What it counts | The count of bounced emails (hard plus soft) per period bucket, plotted as a line over the selected window. |
| API endpoint + statistics field | POST /api/campaign-values-reports and POST /api/flow-values-reports, returning the bounced statistic (with bounce_rate available) per bucket. |
| Email vs SMS aggregation | Email only. SMS uses carrier-level delivery and failure handling, tracked separately under the SMS channel. |
| MPP impact | None. Apple Mail Privacy Protection inflates opens, not bounces, so this line is unaffected by MPP. |
| Chart type | Line. |
| Time window | 30D vsP |
| Alert trigger | A sustained upward trend in bounced emails against the recent baseline, which signals list-hygiene or sender-reputation risk building over time. |
| Roles | owner, marketing |
Calculation
Calculated automatically from your Klaviyo data. See the At a glance summary above for what the metric tracks and the worked example below for a typical reading.Worked example
An illustrative pet-supplies brand that imported an older list segment partway through the month. Reading the dashboard on 14 Apr 26 for the trailing 30 days (14 Mar 26 to 12 Apr 26), the bounce line by week looks like this (illustrative figures):| Week | Delivered | Bounced (hard + soft) | Bounce rate |
|---|---|---|---|
| 14-20 Mar 26 | 94,000 | 470 | 0.50% |
| 21-27 Mar 26 | 95,500 | 478 | 0.50% |
| 28 Mar-3 Apr 26 | 92,000 | 1,288 | 1.40% |
| 4-12 Apr 26 | 96,000 | 1,632 | 1.70% |
- The line is flat at roughly 475 bounces a week, then climbs in weeks 3 and 4. The trend, not any single point, is the signal. A steady baseline that starts rising is the pattern this card is built to surface.
- The rise coincides with an imported older segment. Stale addresses are a classic source of hard bounces, because some recipients no longer exist. The timing points straight at the import as the cause.
- Hard and soft bounces mean different things. Hard bounces (permanent) suggest invalid or dead addresses and call for list cleaning. Soft bounces (temporary) such as full mailboxes may resolve on their own. A persistent rise driven by hard bounces is the more serious of the two.
- A rising bounce line threatens reputation, not just this send. Mailbox providers read elevated bounces as a sign of poor list hygiene, which can quietly lower inbox placement for every future send. That is why a creeping trend deserves action before it becomes a Deliverability Drop.
- The fix is hygiene plus suppression. Clean the imported segment, let Klaviyo suppress hard-bounced addresses, and stop emailing them. Watch Suppressed Profiles rise as the bad addresses are removed and the bounce line settles back toward baseline.
Sibling cards merchants should reference together
Bounce Trend is the trajectory view. Pair it with these to read level, alert, and consequence:| Card | Why pair it with Bounce Trend |
|---|---|
| Bounce Rate | The proportion behind the line. The trend shows direction; the rate shows whether the level is dangerous right now. |
| Bounce Spike | The alert layer. A sudden jump in this line is what the spike alert catches and escalates. |
| Delivery Rate | The mirror image. A rising bounce trend pulls delivery rate down, so the two move in opposite directions. |
| Deliverability Drop | The downstream consequence. A sustained bounce rise often precedes a measurable deliverability fall. |
| Sender Reputation Risk | The composite warning. Rising bounces are one of the inputs to a reputation-risk flag. |
| Suppressed Profiles | The cleanup view. Hard-bounced addresses get suppressed, so this should climb as the bounce trend is brought under control. |
Reconciling against Klaviyo
Where to look in Klaviyo:- Klaviyo → Analytics → Performance, then the bounced or bounce-rate metric over time, for the program-level trend.
- Klaviyo → Campaigns and Klaviyo → Flows, then a specific send’s analytics, where bounces are broken out per send.
- Klaviyo → Analytics → Deliverability, for the broader reputation context behind a rising line.
| Reason | Direction of divergence |
|---|---|
| Hard plus soft. This card combines hard and soft bounces. A view filtered to hard bounces only will read lower than ours. | Ours reads higher than a hard-only view. |
| Time zone. Vortex IQ buckets by UTC day; Klaviyo uses your account time zone. A bounce near midnight can fall into a different period. | Either direction, usually marginal. |
| Bounce vs drop. This card counts attempted-then-rejected messages, not dropped (never-attempted) messages. A view that conflates the two will not match. | Ours reads lower than a bounce-plus-drop view. |
| Campaign plus flow scope. This card blends campaigns and flows. A campaign-only view will read lower. | Ours reads higher than a campaign-only view. |
| Page caps. Values reporting pages at 50 records per pull, so very high send volumes can see slight aggregation truncation. | Ours can read marginally low for heavy senders. |