email all users on new event action hook

Hi
I would like to send an email alert to all members when we add a cycling event.
I have tried the following in the default WP theme Twenty Seventeen functions.php

add_action('eme_insert_event_action','eme_mail_event');
function eme_mail_event ($event) {
   $contact = eme_get_contact ($event);
   $contact_email = $contact->user_email;
   $contact_name = $contact->display_name;
   $subject_format="This is the new event called ' #_EVENTNAME '";
   $body_format="This is the new event called ' #_EVENTNAME '";

   $subject=eme_replace_placeholders($subject_format, $event, "text");
   $body=eme_replace_placeholders($body_format, $event, "text");
   $blogusers = get_users();
   foreach ( $blogusers as $user ) {
      eme_send_mail($subject,$body, $user->email, $user->display_name, $contact_email, $contact_name);
   }
}

But when I create a new event I do not get an email.
I have verified mail does work on the plugin and WP.

What have I missed?
Thanks