How to exclude multiple email addresses from an order query
Agree it'd be nice if it worked that way... I'm not sure why it doesn't, but replacing it with a regular where clause and not in works ok:

$order = Order::find()
    -&gt;isCompleted(true)
    -&gt;where(['not in', 'email', ['nobody@example.com','no@example.com']])
    -&gt;all();