Yes, that has been a rule for many years, BUT ... there is a way around it that I use since some of those envelopes are not the best. Print out your postage online. Then lay the label the long way on the envelope, about an inch from the flap. Now you need to tape your label on, don't you? Use wide packing tape across the label overlapping onto the flap and you're good to go! Alternatively, order the padded ones online. They seem to hold much better.