Ok let's check erm_email_user_last_access   

{PUBLISH_URL} use this value:
$publish_url = osc_item_post_url();
Here is it's definition:
function osc_item_post_url() {
  if (osc_rewrite_enabled()) {
    $path = osc_base_url(false, true) . osc_get_preference('rewrite_item_new');
  } else {
    $path = osc_base_url(true) . '?page=item&action=item_add';
  }
  return $path;
}
Everything is alright on plugin & osclass side as far as I can see.

I'm not saying no, I have absolutely no major problems with Osclass, plugins and so on.

I'm just saying I need help. I don't understand why the messages come as localhost/something

Someone much more experienced than me should agree to make a call and take a look.

That should be you MBThemes, as I have free support for premium items.

Since I bought them all... I would like to get your support please, it will probably be done in 5 minutes.

This is help - it is not problem of osclass.
You can try to edit those email functions and print content of email to error logs so you see how it was constructed and sent.