What Mail Tracking Can (and cannot) Tell You
December 21, 2021   Dave Lewis

Mail tracking isn’t perfect.  There, I said it.  Of course, you should track your mail – every single piece of it – but a well-informed customer is more likely to be a satisfied customer. Understanding some of the limitations can make mail tracking even more valuable to you and your customers.

The holiday season is that magical time of year when mailing is at its peak – that’s why they call it the peak season.  Holiday gift shopping and year-end giving to charities requires on-time delivery, and the ability to react when things are not going as planned.  Informed Visibility, the USPS service that powers SnailWorks mail tracking, provides tracking data on mail container (pallets), trays, mail pieces, and even trucks.  The system also enhances all this data relating one type of scan with another so there can be assumed and logical scans, in addition to actual piece scans.  It’s an enormous amount of data, and that raw data is what SnailWorks uses to create our reports.  It’s pretty fabulous.  But…

Informed Visibility is a passive process.  Generally speaking, it relies on leveraging scan data provided as mail pieces pass through the equipment.  Letter carriers don’t scan each piece of mail – the equipment that sorts it for them does.  Containers are scanned by imperfect hand-held scanners – or sometimes not scanned.  Mail doesn’t always follow a predictable route – there are times when a bundle of flats may end up on package sorting equipment.  Locally, postal management may decide to sort some mail by hand because equipment is backed up and there is available labor. 

Given all of that, the results are remarkably accurate.  Still, some things that can happen:

  • Pallets may not be scanned.  This is particularly important for flats, as we are often working with assumed scans based on those pallet scans.  Induction scan rates for flats are very high – generally better than 95%.  Subsequent piece scans may be hit or miss which is why flat piece scan rates tend to be lower.
  • IV can only scan to the point where the mail is sorted to the carrier – we know when the carrier got it – but we can’t be sure they delivered it.  During COVID there have been carrier shortages in some stations, so not every route is necessarily carried every day.  This is certainly the exception, but it happens.  IV won’t tell you.
  • Logical delivery events are just that.  We logically believe the carrier has the piece in their bag, and when they pass the house, they deliver it.  But there are occasions when they don’t have the piece, so logically it should have been delivered, but no one is scanning to be sure.  There are occasions when the piece is not with the carrier such as when:
  • False “stop-the-clock” scans occur.  For example, there are two scan events associated with sequencing letter mail – operations 918 and 919.  If we, or USPS, sees a 918 scan we treat it as a stop-the-clock event and create a logical delivery event for the next delivery opportunity.  Usually, the scans occurred within an hour or two of one another, but sometimes they are far enough apart that we have already selected the 918 as our stop-the-clock, and declared it delivered.  Then, we may get a poky 919 the next day, and declare it delivered again a day later.  When you see delivery dates move in your reporting, that’s most often the cause – we get rid of the old delivery date and post the newer, more accurate date.
  • Not every piece of mail gets scanned.  Carrier-route flats most often go directly to the delivery unit (DDU), and we count on container and bundle scans.  Some mail doesn’t run well, and operators decide to have it hand sorted.  Some areas of the country just don’t have as much automation equipment (I’m lookin’ at you, Vermont).

All these causes should be for relatively small portions of the mail, but you should know they exist.  IV is still remarkably good at following the delivery of your mail, identifying how long it took to deliver and pointing out delays and their cause. 

Here are a couple of other reasons you may see low scan results that aren’t created by IV:

  • Incorrect piece barcodes.  The wrong MID, STID, or serial number range.  Happens more often than you might think, especially on re-presorted jobs.  In a lot of cases, we can still hunt them down for you.  We may even see pallet scans, because the pallets have the correct barcodes, but not the pieces on them.
  • The mail is still delivering.  Be sure to allow enough time for the mail to deliver.  That’s why you are tracking it. 
  • Poor address quality is pushing mail out of the mail stream.  If the mail piece cannot be delivered as addressed, it may go to a forwarding unit, or to recycling.  Either way, delivery is impacted. 

Naturally, there are many other mysterious things that can impact tracking.  We love figuring those out – don’t hesitate to ask us

Mail tracking is an overwhelmingly good idea, for a more reasons than we can list here.  We just like our customers to know it is not quite perfect – but we’re always working on it!