Greylist API Processing Documentation

The Greylist Validation feature allows you to validate greylisted domains directly with the ZeroBounce API. Whenever you receive an unknown/greylisted result during validation, the email will be reprocessed to provide a result.

There are two options to enable and use this functionality:

1. Pickup

To use the Pickup option, add the following parameter to the normal /v2/validate call:

You can reattempt the validation request after 30 minutes by including the new parameter to obtain a result.

Any duplicate requests will return an error message suggesting to retry later.
{"Message": "Greylist validation still in progress. Please try again later."}

ZeroBounce deducts credits after a successful pickup.

2. Webhook

To create a webhook, add the following two parameters to the normal /v2/validate call:

For webhooks, duplicate requests are allowed. If you make the same request twice, you can expect two callbacks. Each callback will be charged.

When the greylist processing is complete, we will send an HTTP request to your callback_url with the result.

ZeroBounce deducts credits upon a successful callback to the callback_url.

We will consider the callback successful if your endpoint response has status code 200 or 201.