[Yandex Cloud documentation](../../index.md) > [Yandex Cloud Postbox](../index.md) > [Concepts](index.md) > Tracking email openings

# Tracking email openings

In Yandex Cloud Postbox, you can track whether recipients open your emails. When the recipient opens the email in their email client, Yandex Cloud Postbox will send a notification.

## How it works {#how-it-works}

To track email openings, Yandex Cloud Postbox uses a `tracking pixel`. When tracking is enabled, Yandex Cloud Postbox automatically embeds an invisible 1x1 pixel image at the end of the top HTML part of the email.

As soon as the recipient opens the email in an email client, the client loads the images, including the tracking pixel. Yandex Cloud Postbox logs the request to load the pixel and sends a notification that the email has been opened.

For a description of the email opening notification format, see [Email open notification](notification.md#open).

{% note warning %}

Yandex Cloud Postbox modifies the email body by adding a tracking pixel.

{% endnote %}

## How to enable {#setup}

You can enable tracking for email openings when [creating](../operations/create-configuration.md) or editing a configuration by using the following methods:

Method | `Openings` [metric](statistics.md#metrics) collection | Sending notifications to Data Streams
--- | --- | ---
Select the **Email opened** notification type under **Subscriptions**. | ![yes](../../_assets/common/yes.svg) | ![yes](../../_assets/common/yes.svg)
Enable **Engagement statistics** under **Statistics collection settings**. | ![yes](../../_assets/common/yes.svg) | ![no](../../_assets/common/no.svg)

{% note info %}

Tracking works for emails with one recipient only.

The tracking pixel is added only to emails containing an HTML part. You cannot use tracking if your email contains only a text part.

{% endnote %}

## Features {#features}

### Multiple openings {#multiple-opens}

Yandex Cloud Postbox sends a notification each time a recipient opens your email. If the recipient has opened the email several times, you will get as many notifications.

Sometimes, you may get more notifications than the actual number of times the recipient has opened your email for the following reasons:

* The recipient's email client preloads images from emails.
* Your email was exposed to automatic antimalware scanning.
* Other automated processes.

### Caching {#caching}

If the recipient's email client or intermediate servers cache images, repeated openings of the email may not be logged. This depends on the settings of each specific email client.

### Limits {#limitations}

Tracking email openings may not work accurately in the following cases:

* The recipient has disabled image loading in their email client.
* The email is opened in preview mode without loading images.
* The email client blocks any external images by default.
* The email is opened in text mode.