You arent supposed to put any packages over 13 ounces in a drop box/mail box they all have to be taken in and handed to a person for scanning. I didnt know this and I dropped a pair of shoes in the drop box in the post office lobby one evening after hours. Never thought another thing about it, 2 days later I had one of those yellow pick up slips in my box, I go to see what it is. It was my shoes, they didnt scan it because I hadnt followed proper procedure so then the label date was a day off and she said they couldnt legally scan anything that was postmarked/dated for another date. They made me take the shoes back and reprint the label with that days date on it. I was so pissed, I think it's just a case where someone has nothing better to do and decides to make an example. I'd be willing to bet that something similiar has happened that someone yanked it because it wasn't hand delivered to a postal worker and they have stuck it somewhere and have forgotten about it.