Email delivery simulator

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Updated at August 4, 2026

The email delivery simulator is a set of special Yandex Cloud Postbox addresses that simulate different email delivery outcomes.

You can email to the simulator address using any method supported by Yandex Cloud Postbox: SMTP or an AWS-compatible API.

Available addresses

Address	Scenario	Description
`success@simulator.pstbx.ru`	Successful delivery	Yandex Cloud Postbox accepts the email as delivered.
`bounce@simulator.pstbx.ru`	Delivery error	The simulator's mail server returns the `452 4.2.2 The recipient's inbox is out of storage space` SMTP response.
`delay@simulator.pstbx.ru`	Delivery delayed	Yandex Cloud Postbox fails to deliver the email due to a temporary error, sends a delivery delayed notification, and retries delivery.
`suppressed@simulator.pstbx.ru`	Recipient on suppression list	Yandex Cloud Postbox does not attempt to deliver the email and sends a delivery error notification with the `Suppressed` subtype, as if the recipient address were on the suppression list.

Get ready to send an email using one of the methods described in Sending an email.
Specify the simulator address for your preferred scenario as a recipient.
Send an email.
Check the result:
- In email operation notifications if your email uses a subscription configuration.
- In the statistics.
- In the execution log if transitions between email statuses are logged for the address.
- In sent history.