The factors which should be known before trying to guess how late USPS delivers your emails and package on any given day are the labor costs as well as the cost involved to hand deliver mail to almost each and every single address in the country irrespective of urban or rural locations. As it can clearly be understood that this shoots up the postage rates and just to keep the rates as low as possible, the USPS tries to compensate by employing less number of carriers that might be needed to cover a particular area on most working days. On top of that, deliveries are done six days a week whereas each employee is only scheduled five days a week like every other business in the country.
So as to cover the deliveries on all those 6 days and then to tackle usual business obstacles such as sick calls, heavy volume days, vacation days etc. regular adjustments are an absolute must to their daily delivery schedules made. Apart from that, it should be noted that the time taken for each delivery remains almost the same on most days even if a particular house gets no mail or gets twenty pieces of them since the carrier still needs to pass by that house. A must mention here before starting the discussion on how late USPS delivers is that USPS packages are generally delivered by the regular letter carrier and not anyone specially assigned for this task. Hence, it should be understood that once that regular letter carrier of your respective area has already delivered on any particular day, then it is highly likely that there will most probably be not another late delivery on that very day.
Moreover, their tracking system is nothing obsolete or outdated and does a decent job even when compared to the likes of UPS or even FedEx. In most cases, the message which says "electronic notice received" actually points to the fact that the package you are eagerly expecting is yet to be delivered to the Post Office by the shipper. All that has been done up to that point, is simply a shipping label that was created online. In most cases. Amazon simply passes you the tracking number that is received from USPS instead of tracking anything on their own. The timing of delivery and whether it is going to be delivered late or not greatly varies depending upon the volume of mail that is processed on that particular day.
In general, mail starts getting delivered to the P O Boxes of USPS stations around half past eight in the morning. There is a provision that you may claim your money back if you don't get your domestic express mail delivered on any working day before noon. Similarly, every single international express mail is supposed to be delivered on or before 3 pm. Along with that, all the packages and domestic packages should get delivered as and when your city carrier visits your respective region to deliver emails. Lastly, all other mail, as well as the parcels, are strictly taken out for delivery by 5 pm local time.
