GLS will send you an email upon receipt of your package in their service, before delivering you.
As soon as it is scanned for the first time, you will receive an email indicating the day and a time slot (3 hours) for delivery.
If you realize that you can't be there, don't worry! A phone number and a link is sent to you to be able to change the delivery day :-)
If you could not change the delivery day and you were not on site, your package will be put to the nearest Mondial Relay point.