If you have a multi-author WordPress blog and you allow guest blogging, then your often need to send an email notification after you review and publish their post.
The following code snippet will help you to send an email to the post author after post is live. Just add the following snippets to your theme function.php file.
add_action( 'transition_post_status', 'post_published_notification' , 10, 3 );
function post_published_notification($new_status, $old_status, $post ) {
if ( 'publish' !== $new_status or 'publish' === $old_status)return;
$author = $post->post_author;
$name = get_the_author_meta( 'display_name', $author );
$email = get_the_author_meta( 'user_email', $author );
$post_title = $post->post_title;
$permalink = get_post_permalink($post);
$admin_email = get_option('admin_email');
$subject = 'Congratulations! Your article has been published!';
$headers = "MIME-Version: 1.0" . "\r\n";
$headers .= "Content-type:text/html;charset=UTF-8"."\r\n";
$headers .= 'From: Stacktips <'. $admin_email . ">\r\n" . 'Reply-To: Stacktips <' . $admin_email . ">\r\n";
$message = <<<MESSAGE
<html><body>
<p>Dear {$name}!</p>
<p>Congratulations! Your article titled <strong>{$post_title}</strong> has been published on {$site_name}</p>
</body></html>
MESSAGE;
wp_mail($email, $subject, $message, $headers);
}