It's been said a few times already, but I want to reiterate that at the moment MyUsps is more unreliable than ever. USPS is working on major upgrades to their tracking system, and some packages that have appeared on MyUsps for years are now not showing up at all. In the past two weeks, I've had two packages not show up at all, even after delivery. Both packages were delivered in the normal 2-3 days. These packages have popped up on MyUsps every time in the past.
That being said, as customers it's our job to NOT drive our vendors crazy. I'm not a vendor, but I do know that many receive dozens of messages a day from us paranoid folk wondering where our packages are. Most vendors provide a timetable stating how long one should wait before asking about tracking. Also, remember that since we are in the holiday season it's not uncommon for priority packages to take a week or longer.
TL;DR Packages that have appeared on MyUsps in the past may no longer show up. Don't drive your vendor crazy with messages asking where your package is.
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