Is my postal mail going to be returned?

I recently mailed out an envelope and put a small object in it, about the size and shape of a package of gum. It stil weighs less than an ounce, and I put one stamp on it.



Is that okay that there is an object in there or will it be returned to my address for some reason?



I'm new to snail mail..Is my postal mail going to be returned?
I think that's too thick to qualify as a "letter". I doubt that it would fit through the sorting machines they use, so any of a few things could happen. It could be returned for insufficient postage (because it would be considered a "package" due to the thickness and therefore need more postage), it could get torn apart going through the sorting machine because it's too thick to fit through it, or someone might notice it's too big and process it by hand and possibly charge the recipient for the extra postage due. I suppose it could actually get delivered, but I think that's probably the least likely option.



Here's a website with the limitations on the size of a "letter": http://pe.usps.com/businessmail101/mailc鈥?/a>