Days into the new year and people are still receiving holiday mail. That's because some envelopes are literally getting caught in the system.

Kevin Burke received a friend's Christmas card neatly wrapped in a Postal Service plastic bag. "Damaged by mechanical equipment, please accept our apology, U.S. Postal Service. I think it's just something that happens during the Christmas event, but it's kind of funny."

Omaha Postal Service spokesman Roger Humphries says more cards were opened at the post office by sorting machines during this holiday season. “This card is obviously thicker than the envelope and it's actually pushing and it actually comes out."

Some types of envelope paper just tear easily. "They're so paper thin, almost like tissue paper in some cases, that as the cards fly through our automated system, they're actually falling apart and getting torn,” says Humphries.

The Postal Service isn't just seeing problems with envelopes on greeting cards, but also photographs. Many people write "do not bend" on an envelope and think that's enough, but if there's not support inside, when it goes through the sorting machines, it will bend.

“It actually has cardboard in it, so just anything that is nice and strong keeps it from bending,” says Humphries. That cardboard support could save an engagement or graduation photo from suffering the bends.

Even into the new year, the Postal Service is trying its best to deliver everyone's holiday mail, sometimes piece by piece. “We do care, we do, and we want to get these to them," says Humphries.

The Postal Service is communicating with envelope manufacturers about the types of paper that are getting caught in sorting machines. Hopefully by next holiday season, fewer cards will be opened before they get to your mailbox.