Codeception Mocking \Mail Cest

I can't seem to Mock a mail call for a codception test. This is what I'm trying, but the mocked object is never called. Does anyone have a clue why this would be the case. I'm pretty sure it's the wrong ioc object.

$I->haveBinding('mailer',function(){
    $mail = \Mockery::mock(Mailer::class);
    $mail->shouldReceive("send")->with(\Mockery::any(),\Mockery::any(),\Mockery::any())->once();

    return $mail;

});

via Chebli Mohamed