Returns aggregate delivery and engagement counts grouped by broadcast for the requested period, so each broadcast's deliverability and engagement can be compared side by side. Only messages sent as part of a broadcast appear here; one-off and transactional sends are not included, so a workspace that has not sent broadcasts returns an empty list rather than an error. Rows are ranked by the `sort` metric (default `processed`) descending and capped at the requested `limit` (default 50, hard maximum 200). Rows are computed against event time (not send time), so engagement received during the period for messages sent earlier is included. The maximum window is 365 days; requesting a longer range returns 422. Start date (inclusive) in YYYY-MM-DD, UTC. Defaults to 30 days before `to` when omitted; with `include_trend=true` and `trend_grain=hourly` the default tightens to 29 days before `to`, keeping the defaulted window within the 720-hour trend cap. End date (inclusive) in YYYY-MM-DD, UTC. Defaults to today (UTC) when omitted. Window may not exceed 365 days. Email statistics are aggregated across all categories. Per-category filtering is not yet available; supplying this parameter returns 422. Metric to rank rows by, applied descending. Any count or rate in the response may be used; rows whose rate is undefined (zero denominator) sort last. Defaults to `processed`. Maximum number of broadcast rows to return, ranked by the `sort` field descending. When true, each row also carries a `trend` array: a short per-bucket series of that broadcast's delivery and engagement rates over the window. Once available it will be returned only when `limit` is 50 or fewer and the window is at most 90 days (trend_grain=daily) or 720 hours (trend_grain=hourly); a larger request returns 422. When `from` is omitted and `trend_grain=hourly`, the default window is 30 days (720 hours), so a request built entirely from defaults always fits the cap. This parameter is not yet available; supplying it returns 422. Bucket grain for the `trend` series. Has no effect unless `include_trend=true`, which is not yet available. Inclusive start date the response covers (YYYY-MM-DD). Inclusive end date the response covers (YYYY-MM-DD). The instant the statistics in this response are current to: events recorded up to roughly this time are reflected, while more recent events may not be yet. Statistics are served from a rolling aggregation that refreshes every few seconds, so a response is near-real-time but not live; use this field to label data freshness (for example "as of 14:03") rather than assuming the numbers are to-the-second. Null when the freshness boundary is not being reported. Broadcast breakdown rows, ranked by the `sort` metric (default `processed`) descending. Empty when no broadcast messages were active in the period. The broadcast this row aggregates, the same identifier returned by the broadcast endpoints. Only messages sent as part of a broadcast carry a broadcast identifier; one-off and transactional sends are not included in this breakdown. Distinct recipients accepted for delivery after suppression filtering. Reported on time buckets and the period summary; omitted on breakdown rows, whose rollups do not carry it. Distinct recipients whose message was processed and handed off for delivery. Distinct recipients whose message the receiving mail server accepted. Distinct recipients whose delivery failed. Approximately the sum of the five `bounces.*` sub-counts (hard, soft, admin, block, undetermined); the totals are computed independently so they may differ slightly at the approximation error. Distinct recipients with a permanent delivery failure (invalid address or non-existent domain). Distinct recipients with a transient delivery failure (mailbox full or server temporarily unavailable). Distinct recipients bounced by an upstream policy block (relaying denied, blocklisted domain). Distinct recipients bounced because the receiving mail server blocked the sending IP for reputation reasons. Distinct recipients bounced where the receiving server's response did not allow precise classification. Fraction of bounced recipients that hard bounced, computed as `hard / bounced`. Null when `bounced` is zero. Fraction of bounced recipients that soft bounced, computed as `soft / bounced`. Null when `bounced` is zero. Fraction of bounced recipients that admin bounced, computed as `admin / bounced`. Null when `bounced` is zero. Fraction of bounced recipients that block bounced, computed as `block / bounced`. Null when `bounced` is zero. Fraction of bounced recipients with undetermined classification, computed as `undetermined / bounced`. Null when `bounced` is zero. Distinct recipients who reported the message as spam via a feedback loop. Distinct recipients whose delivery the receiving server temporarily delayed and is still being retried. Distinct recipients rejected before any delivery attempt. Includes recipients on the workspace suppression list, transmissions that could not be completed, message-generation failures, and recipients refused by sending policy. The per-recipient `rejection_reason` field on `GET /v1/email/messages/{message_id}/recipients` surfaces the specific cause. Out-of-band bounce events: distinct failure notifications received after the receiving server had initially confirmed delivery. Counted as deduplicated events, not unique recipients. Recipients who remain in-inbox in this scope after all bounce signals resolve, computed as `delivered - oob_bounces`. Use this as the base for engagement-rate denominators. Clamped to 0 when `oob_bounces` exceeds `delivered`. Total recipients in this scope who did not receive the message, computed as `bounced + oob_bounces`. Share of this scope's delivery attempts that resulted in an out-of-band bounce, computed as `oob_bounces / (delivered + bounced)`. Null when there were no attempts. Share of this scope's delivery attempts that resulted in a message remaining in-inbox, computed as `effective_delivered / (delivered + bounced)`. Null when there were no attempts. Share of this scope's delivery attempts that ultimately failed (inband or out-of-band), computed as `all_bounces / (delivered + bounced)`. Null when there were no attempts. Spam complaints in this scope relative to effectively delivered recipients, computed as `complained / effective_delivered`. Complaints are attributed by event time, so a scope can record more of them than it effectively delivered, pushing the rate above 1. Null when `effective_delivered` is zero. Distinct open events, counting repeat opens from the same recipient and opens auto-fetched by inbox privacy features (such as Apple Mail Privacy Protection and the Gmail image proxy). Distinct open events excluding those auto-fetched by inbox privacy features. Same event-counting semantics as `opens` (repeat opens from the same recipient count separately), with prefetched opens removed. Distinct recipients who opened at least once, including opens auto-fetched by inbox privacy features. Distinct recipients who opened at least once, excluding opens auto-fetched by inbox privacy features. This is the numerator used for open rate, so iOS-heavy audiences (Apple Mail Privacy Protection and similar) do not inflate it. Distinct click events, counting repeat clicks from the same recipient. Distinct recipients who clicked at least once. Distinct unsubscribe events, recorded via the list-unsubscribe header or the footer link. Distinct non-prefetched openers relative to recipients delivered in the same scope, computed as `unique_opens_non_prefetched / delivery.delivered`. The numerator excludes opens auto-fetched by inbox privacy features. Opens are attributed by event time, so engagement earned by earlier deliveries can push the rate above 1. Null when `delivery.delivered` is zero. Distinct clickers relative to recipients delivered in the same scope, computed as `unique_clicks / delivery.delivered`. Clicks are attributed by event time, so engagement earned by earlier deliveries can push the rate above 1. Null when `delivery.delivered` is zero. Unsubscribes relative to recipients delivered in the same scope, computed as `unsubscribes / delivery.delivered`. Unsubscribes are attributed by event time, so the rate can exceed 1. Null when `delivery.delivered` is zero. p50, p95, and p99 latency percentiles in milliseconds for one latency family over the bucket. Percentiles are approximate (computed from a high-volume aggregation pipeline). All three are null together when no qualifying event contributed a latency measurement in the bucket. Median (50th percentile) latency in milliseconds. Null when no qualifying event contributed a measurement. 95th percentile latency in milliseconds. Null when no qualifying event contributed a measurement. 99th percentile latency in milliseconds. Null when no qualifying event contributed a measurement. p50, p95, and p99 latency percentiles in milliseconds for one latency family over the bucket. Percentiles are approximate (computed from a high-volume aggregation pipeline). All three are null together when no qualifying event contributed a latency measurement in the bucket. Median (50th percentile) latency in milliseconds. Null when no qualifying event contributed a measurement. 95th percentile latency in milliseconds. Null when no qualifying event contributed a measurement. 99th percentile latency in milliseconds. Null when no qualifying event contributed a measurement. p50, p95, and p99 latency percentiles in milliseconds for one latency family over the bucket. Percentiles are approximate (computed from a high-volume aggregation pipeline). All three are null together when no qualifying event contributed a latency measurement in the bucket. Median (50th percentile) latency in milliseconds. Null when no qualifying event contributed a measurement. 95th percentile latency in milliseconds. Null when no qualifying event contributed a measurement. 99th percentile latency in milliseconds. Null when no qualifying event contributed a measurement. Per-bucket rate series for this broadcast over the window. Present only when `include_trend=true`. The day (YYYY-MM-DD) or hour (ISO 8601, on the hour) this point covers, matching the requested `trend_grain`. Delivered recipients in this bucket. Bounced recipients in this bucket. Delivery rate for this bucket, as a fraction. Null when nothing was delivered or bounced. Bounce rate for this bucket, as a fraction. Null when nothing was delivered or bounced. Complaint rate for this bucket, as a fraction; event-time attribution can push it above 1 when complaints outrun the bucket's deliveries. Null when nothing was delivered in the bucket. On a sending-IP row complaints are not attributed to the IP, so this reads 0 in buckets that had deliveries and null in buckets that had none. Open rate for this bucket, as a fraction; event-time attribution can push it above 1 when opens outrun the bucket's deliveries. Null when nothing was delivered in the bucket. On a sending-IP row engagement is not attributed to the IP, so this reads 0 in buckets that had deliveries and null in buckets that had none. Click rate for this bucket, as a fraction; event-time attribution can push it above 1 when clicks outrun the bucket's deliveries. Null when nothing was delivered in the bucket. On a sending-IP row engagement is not attributed to the IP, so this reads 0 in buckets that had deliveries and null in buckets that had none. Total number of distinct broadcasts with activity in the period, regardless of `limit`. When it exceeds the number of rows returned, the ranking was capped; raise `limit` (up to 200) or narrow the window to see more.