The holidays are fast approaching which means it is time to start sending out those holiday post cards. But there could be some problems.

Christmas, Chanukah, and Kwanzaa cards come in all shapes and sizes.

But square cards are a problem for the post office.

Sorting machines are built to read rectangles, and they cannot find addresses on square envelopes.

So if you go with the square cards this year, be sure to include the extra postage for hand sorting. That is 58 cents per envelope, compared to 41 cents.