mailing cards

i am a retired U.S. Postal Service employee. My job there was to run the machine that put the cancelation mark on the stamp, my wife's job was to repair everything that got wrecked in the machines. If you want to be sure all of your Christmas cards get there, do not trust the glue on the flap. And do not think some little sticker in the middle of the flap will work either. Tape the entire flap shut. All of the machines in the post office are loaded with sorting gates. If a piece of mail gets in the machine where the flap is not sealed, the gates become letter openers. Often times an open flap letter will get hung up on a gate and with the speeds the machines run a "train wreck" will happen. The trian wreck will then often be removed with pliers, usually doing damage to all the mail that was involved in the wreck. This time of year my wife and at least 3 other people would work 12 hours a day repairing mail....