Returns a single-row aggregate across the requested period covering delivery, bounce, complaint, open, and click counts plus the derived rates, along with processing, delivery, and total latency percentiles (p50/p95/p99) for the period. Suitable for KPI tiles, dashboard headers, and email digests. Rows are computed against event time (not send time), so engagement received during the period for messages sent earlier is included. Rate fields are null when their denominator is zero — for example, `open_rate` is null in a period where nothing was delivered. `from` and `to` accept either calendar days (YYYY-MM-DD) or RFC 3339 instants. With days the window covers whole calendar days, up to 365 days. With instants the window is hour-grain — bounds round down to the hour, both inclusive — so a rolling window such as the last 24 hours is a single request; hour windows may span up to 720 hours (30 days), and `compare=previous_period` compares against the preceding equal-length hour window. Both bounds must use the same form; mixing a day and an instant returns 422. Set `timezone` to report in a local zone instead of UTC (it then governs the day and hour boundaries; see `timezone`). The full window is available in any timezone. Inclusive start of the window: a calendar day (YYYY-MM-DD) or an RFC 3339 instant (rounded down to the hour). Interpreted in `timezone` -- a calendar day names a local day and an instant is rounded down to the local hour -- or in UTC when `timezone` is omitted. A numeric UTC offset (for example `+05:45`) is rejected when `timezone` is set; use a calendar day or a `Z` (UTC) instant. Must use the same form as `to`. Defaults to 30 days before `to` for day windows, or 168 hours (7 days) before `to` for hour windows, when omitted. Inclusive end of the window: a calendar day (YYYY-MM-DD) or an RFC 3339 instant (rounded down to the hour). Interpreted in `timezone` -- a calendar day names a local day and an instant is rounded down to the local hour -- or in UTC when `timezone` is omitted. A numeric UTC offset is rejected when `timezone` is set; use a calendar day or a `Z` (UTC) instant. Must use the same form as `from`. Defaults to today for day windows, or the current hour for hour windows, in that timezone, when omitted. Day windows may not exceed 365 days; hour windows may not exceed 720 hours (30 days). IANA timezone identifier (for example `Asia/Kathmandu` or `America/New_York`) to report the statistics in. It is the single source of timezone: day and hour boundaries, and the relative window defaults used when `from` and `to` are omitted, are computed in this timezone instead of UTC, so a timezone with a sub-hour offset (such as India at +05:30 or Nepal at +05:45) still gets correct local-day and local-hour totals. When it is set, a `from` or `to` given as a calendar day names a local day in this timezone, and one given as an instant stays an absolute point in time but is rounded down to its hour and bucketed in this timezone (so the hour boundaries are local, not UTC). To avoid specifying the zone twice, a `from` or `to` that carries its own numeric UTC offset (for example `+05:45`) is rejected when `timezone` is set; use a calendar day or a `Z` (UTC) instant instead. Defaults to UTC. Restrict the statistics to a single category: `transactional` or `marketing`. Mutually exclusive with the other dimension filters; only one may be set per request. Restrict the statistics to a single sending domain (the part of the From address after @). Mutually exclusive with the other dimension filters; only one may be set per request. Restrict the statistics to a single tag. Use `name` to match any value of a tag, or `name:value` for a specific pair (for example `campaign:spring_launch`). Mutually exclusive with the other dimension filters; only one may be set per request. Restrict the statistics to a single sending IP. Mutually exclusive with the other dimension filters; only one may be set per request. A sending IP is only assigned once a message reaches delivery, so an IP-filtered result reports delivery-side metrics only: accepted, processed, rejected, complaint, and engagement counts are 0 and the processing latency is null; complaint, open, and click rates read 0 when there were deliveries and null when there were none. Restrict the statistics to a single recipient mailbox domain (the part of the recipient address after the `@`, for example `gmail.com`). Mutually exclusive with the other dimension filters; only one may be set per request. Restrict the statistics to a single template, by its ID (`emt_…`) or its name. Mutually exclusive with the other dimension filters; only one may be set per request. Set to `previous_period` to also include the same statistics for the immediately preceding window of equal length, plus the change between the two, so you can show "+X% vs last period" without a second request. Inclusive start of the window the response covers -- a calendar day (YYYY-MM-DD, UTC) for day windows, or an hour boundary (RFC 3339) for hour windows. Inclusive end of the window the response covers -- a calendar day (YYYY-MM-DD, UTC) for day windows, or an hour boundary (RFC 3339) for hour windows. 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. Distinct email messages accepted, counted at the message level (one per accepted send regardless of recipient count) and summed per day across the period. This counts messages, not recipients, so it is not comparable to `delivery.accepted`, which counts recipients -- a single message to 500 recipients is 1 here and up to 500 there. 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. Inclusive start of the window the response covers -- a calendar day (YYYY-MM-DD, UTC) for day windows, or an hour boundary (RFC 3339) for hour windows. Inclusive end of the window the response covers -- a calendar day (YYYY-MM-DD, UTC) for day windows, or an hour boundary (RFC 3339) for hour windows. 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. Distinct email messages accepted in the preceding period, counted at the message level. 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. Relative change in accepted messages (the `sends_accepted` count) versus the previous period, as a signed fraction. Null when the previous period accepted none. Relative change in delivered recipients (`delivery.delivered`) versus the previous period, as a signed fraction. Null when the previous period delivered none. Relative change in bounced recipients (`delivery.bounced`) versus the previous period, as a signed fraction. Null when the previous period had none. Relative change in spam complaints (`delivery.complained`) versus the previous period, as a signed fraction. Null when the previous period had none. Relative change in unique non-prefetched opens (`engagement.unique_opens_non_prefetched`, the same count the open rate uses) versus the previous period, as a signed fraction. Null when the previous period had none. Signed difference between this period's and the previous period's delivery rate, both fractions in [0,1] (multiply by 100 for percentage points). Null when either period's delivery rate is undefined. Signed difference between this period's and the previous period's open rate, both fractions (multiply by 100 for percentage points). Null when either period's open rate is undefined. Signed difference between this period's and the previous period's click rate, both fractions (multiply by 100 for percentage points). Null when either period's click rate is undefined. Signed difference between this period's and the previous period's bounce rate, both fractions in [0,1] (multiply by 100 for percentage points). Null when either period's bounce rate is undefined. Signed difference between this period's and the previous period's complaint rate, both fractions (multiply by 100 for percentage points). Null when either period's complaint rate is undefined. Signed difference between this period's and the previous period's unsubscribe rate, both fractions (multiply by 100 for percentage points). Null when either period's unsubscribe rate is undefined.