Computer program products, methods, systems, apparatus, and computing entities for generating notifications/messages are provided. In one embodiment, logical groupings associated with items to be delivered are stored. The shipping data for the items can comprise item identifiers and logical grouping identifiers. By using a current logical grouping identifier, it can be determined when an item from a new logical grouping is being or has been delivered. Responsively, notifications/messages can be generated for the new logical grouping to indicate (a) a time window within which the items of the new logical grouping are expected to be delivered or (b) whether a pick-up can be made within the time window.