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filter is not described

is_email_address_unsafe filter-hook . WP 3.5.0

Filters whether an email address is unsafe.

Usage

add_filter( 'is_email_address_unsafe', 'filter_function_name_2595', 10, 2 );
function filter_function_name_2595( $is_email_address_unsafe, $user_email ){
	// filter...

	return $is_email_address_unsafe;
}
$is_email_address_unsafe(true/false)
Whether the email address is "unsafe".
Default: false
$user_email(string)
User email address.

Where the hook is called

is_email_address_unsafe()
wp-includes/ms-functions.php 413
return apply_filters( 'is_email_address_unsafe', $is_email_address_unsafe, $user_email );

Where the hook is used (in WP core)

Does not used.