How to Block Email Addresses in WordPress

Here is a solution to Block Disposable Email Addresses in WordPress in order to resolve registration spam.

Here is a solution to only allowed selected domains to register on your WordPress website.

// Allow Registration Only from @ email addresses

function is_valid_email_domain($login, $email, $errors ){
$valid_email_domains = array(“”,””,””);// allowed domains change as needed
$valid = false; // sets default validation to false
foreach( $valid_email_domains as $d ){
$d_length = strlen( $d );
$current_email_domain = strtolower( substr( $email, -($d_length), $d_length));
if( $current_email_domain == strtolower($d) ){
$valid = true;
// Return error message for invalid domains
if( $valid === false ){

$errors->add(‘domain_whitelist_error’,__( ‘<strong>ERROR</strong>: Registration is only allowed from selected approved domains. If you think you are seeing this in error, please contact us.’ ));
add_action(‘register_post’, ‘is_valid_email_domain’,10,3 );

Place this code in your theme’s functions file – preferrable in a child theme you created or else you will need to update it with each theme update.
See it in action on this site.

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