The normal parsley-validation during input like "must be a valid email-address" still works. But the submit-validation of parsley which prevents submission of the form is required fields are missing doesn't work for me once invisiblerecaptcha is installed. It seems the validation is triggered, but even if it fails the captcha-validation kicks in, verifies the captcha is fine and submits the form. Missing required-fields are then only detected by the server-side validation of powermail 5.x.