A device for processing mail items, having: at least one stacking device for forming a bundle of superimposed mail items and moving it from a forming position to a loading position; one or more robots for removing the bundles in the loading position and moving them into a covering position; one or more covering devices for placing upside down containers over the bundles in the covering position, so the bundles of mail items are housed inside the containers; a conveying system supplied by the covering devices with bundles of mail items covered with respective upside down containers; and a turnover device for turning the containers over through 180°, so the containers are positioned with their respective openings facing upwards.