---
title: blacklist and unblacklist
slug: campaign/docs/blacklist-and-unblacklist
docTags: 
createdAt: 2026-07-02T19:01:45.566Z
---

Blocklist entries can be individual recipients (i.e., an email address) or wildcards, which block all recipients that match a defined pattern (e.g., a whole domain). Use a question mark (?) for a single character and an asterisk (\*) for several characters.

:::hint{type="info"}
**Note**
If the blocklist entry pattern contains special characters, the pattern must be URL-encoded. For example, use the code %2f for a forward slash (/), %252f for a double slash (//), *%2B* for a plus sign (+) etc.
:::

These operations are available in the form service.

**Parameters**

| Name      | Mandatory | Default value | Description                                                                                                                                                 |
| --------- | --------- | ------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------- |
| bmPattern | yes       | –             | If the blocklist entry refers to a single recipient, the email address can be set here. To blocklist multiple recipients, use wildcards as described above. |
| bmReason  | no        | http-api      | The reason for blocking.                                                                                                                                    |

**Return values**

| **Value**                | **Description**                                                                                                                                                                                                                                                                                                                                                |
| ------------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| ok                       | **blocklist**: Entry successfully added to the blocklist.<br />**unblocklist**: Entry successfully removed from blocklist.                                                                                                                                                                                                                                     |
| ok: already\_blacklisted | Only with **bmVerbose=true**: The entry already exists in the blocklist.                                                                                                                                                                                                                                                                                       |
| ok: already\_blacklisted | Only with **bmVerbose=true**: The entry already exists in the blocklist.                                                                                                                                                                                                                                                                                       |
| wrong\_tag               | Authorization failed.<br />Error codes:<br />- 501=wrong authentication tag<br />- 502=wrong request IP<br />- 503=wrong request method<br />- 504=wrong protocol<br />- 505=wrong recipient list<br />- 506=wrong action<br />- 507=action not found<br />If a verification of the authentication tag does not solve the problem, contact *customer support*. |
| missing\_id              | No **bmRecipientId** was transmitted (mandatory) when using the form service.                                                                                                                                                                                                                                                                                  |
| system\_error            | A general error has occurred                                                                                                                                                                                                                                                                                                                                   |

**Example 1**

```javascript
.../form/.../blacklist?bmPattern=john.smith%40example.com
```

The recipient with the ID [\_john.smith@example.com\_](#) is blocked.

**Example 2**

```javascript
.../form/.../unblacklist?bmPattern=john.smith%40example.com
```

The recipient with the ID [\_john.smith@example.com\_](#) is removed from the blocklist.

**Example 3**

```javascript
.../form/.../blacklist?bmPattern=%2A%40example.com
```

All recipients with an email address containing the domain *example.com* are blocked.