> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mailchannels.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Metrics

> Learn how to query engagement, delivery, and sending volume metrics.

## Introduction

The Metrics API provides analytics and visibility into your email sending performance. By leveraging these endpoints, you
can monitor performance indicators, track user engagement, analyze delivery outcomes, and gain valuable insights into
recipient behavior patterns.

MailChannels groups metrics into five categories:

* **[Engagement](/email-api/metrics-engagement)**: opens and clicks.
* **[Performance](/email-api/metrics-performance)**: processed, delivered, and bounced counts.
* **[Volume](/email-api/metrics-volume)**: processed, delivered, and dropped counts.
* **[Recipient Behavior](/email-api/metrics-recipient-behavior)**: unsubscribe activity.
* **[Sender Breakdown](/email-api/metrics-senders)**: aggregate delivery performance grouped by campaign or sub-account.

## Common parameters

All metric queries accept the same time filter:

* `start_time` and `end_time`: ISO 8601 timestamps that restrict the query to a time range. If omitted, `start_time` defaults
  to one month ago and `end_time` defaults to the current time.

Engagement, performance, volume, and recipient behavior additionally accept:

* `campaign_id`: restrict results to a single campaign.
* `interval`: controls bucket granularity for the time series. Supported values: `hour`, `day` (default), `week`, `month`.

Sender breakdown is an aggregate, not a time series, and accepts a different set of parameters. See [sender breakdown](/email-api/metrics-senders)
for details.

<Info>
  Engagement metrics require open and click tracking to be enabled, which is not available in the free tier.
</Info>