---
title: nop
slug: campaign/docs/nop
docTags: 
createdAt: 2026-07-02T19:01:46.737Z
---

The operation **nop** is available in the mail and the form service.

**Parameters**

| Name          | Mandatory | Default value | Description                |
| ------------- | --------- | ------------- | -------------------------- |
| any parameter | no        | –             | For testing purposes only. |

**Return values**

| Value         | Description                                                                                                                                                                                                                                                                                                                                                    |
| ------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| ok            | Operation **nop** successfully performed; i.e., the test was successful.                                                                                                                                                                                                                                                                                       |
| 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*. |
| system\_error | A general error occurred.                                                                                                                                                                                                                                                                                                                                      |

**Example**

```javascript
.../mail/.../nop?bmUrl=http://www.example.com
```

The recipient of the email is forwarded to [www.example.com](http://www.example.com) if the recipient clicks any link.