### [wpforms_mailcheck_toplevel_domains](https://wpforms.com/developers/wpforms_mailcheck_toplevel_domains/)

**Published:** May 21, 2021
**Author:** Editorial Team

**Excerpt:** The wpforms_mailcheck_toplevel_domains filter fires as the Email Address field is completed to check for the top-level email domain suggestion within the form.

**Content:**

## Description

The `wpforms_mailcheck_toplevel_domains` filter fires as the **Email Address** field is completed to check for suggested email domains.

## Parameters

$domains*(array)* An array of top-level domains for the email suggestion.## Source

`wpforms/src/Frontend/Frontend.php`

## More Information

The `wpforms_mailcheck_toplevel_domains` filter can be used to define top level email domain suggestions for the **Email Address** form field.

## Example

```

/**
 * Check for top-level email domain suggestions.
 *
 * @link    https://wpforms.com/developers/wpforms_mailcheck_toplevel_domains/
 *
 * @param   array  $domains An array of top-level domains for the email suggestion.
 * @return  array
 */

function wpf_dev_mailcheck_toplevel_domains( $domains ) {
 
    $domains[] = 'xyz';
 
    return $domains;
}
 
add_filter( 'wpforms_mailcheck_toplevel_domains', 'wpf_dev_mailcheck_toplevel_domains', 10, 1 );

```

A top-level domain (TLD) is the last segment of text in a domain name, such as .com or .net.

## Reference Articles

[How to Add Domains to the Email Suggestion List](https://wpforms.com/developers/how-to-add-domains-to-the-email-suggestion-list/ "How to Add Domains to the Email Suggestion List")

**Categories:** Filters Hooks

**Tags:** PHP

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