title: Edit the WordPress Activation Email
body: <p>Is it possible to amend the content of the Activation email that is sent to users when they sign up for an account on a WordPress site?</p>
  
  <p>I am looking to change the subject and the body of the email to read something a little more in line with my website's information.</p>
  
  <p>I have tried to added the following into a custom plugin found inside mu-plugins, but it seems to have no affect at all:</p>
  
  <pre><code>&lt;?php
  /*
  Plugin Name: Disable Username and Password Notification
  Description: Disables the Username and Password email
  */
  // Start changing email body
  function myprefix_change_activation_email_body ($old_body, $domain, $path, $title, $user, $user_email, $key, $meta) {
      $my_message = "Hi! This is my new email! ";
      $my_message .= "Your site {$title} is almost ready. We probably also want to include the activation key: {$key} ";
      $my_message .= "Activate your site here : http://{$domain}{$path}wp-activate.php?key=$key";
      // ... other stuff
      return $my_message;
  }
  add_filter('wpmu_signup_blog_notification_email', 'myprefix_change_activation_email_body', 10, 8);
  // End changing email body
  
  // Start changing email subject
  function myprefix_change_activation_email_subject ($old_subject, $domain, $path, $title, $user, $user_email, $key, $meta) {
      $my_subject = "Hi! You just registered on my site!";
      return $my_subject;
  }
  add_filter('wpmu_signup_blog_notification_subject', 'myprefix_change_activation_email_subject', 10, 8);
  // End changing email subject
  </code></pre>
  
  <p>From what I can tell, the issue is that the filter being used is most likely for MultiSite setups which my site is not.  It is just a standard WordPress site.</p>
  
  <p>Cheers</p>