So some of us here participated in a holiday card swap........imagine my surprise when I got only the front of an envelope from Connie, but with a card signed by someone named "Bill".  The envelope had been shredded but my address and her return label were still presentable.  They must have matched up my partial envelope with a random loose card!

there is a bad batch of cards out there where the envelopes are so brittle that they don't hold up during normal mail processing. The envelopes literally fall apart. Most times the Post Office still matches up the right card with the right pieces of envelope, but not always. 

I retired in February this year, and for the past couple years at Christmas time we started seeing this type of envelope Brandy L. is talking about.  I'm guessing the stationers are getting their envelopes from China.

Years ago the PO sent me a letter that was shredded up with a lot missing. The PO put it in a ziplock bag with a note of apology and how they make every effort to deliver the mail.   The person who sent it to me was sending me a letter almost every day.  I wonder if the PO checked my future mail and matched the handwriting to the shredded mail for an address.  I was impressed!