The Postman (sometimes) Commeth

We had an issue with postal delivery recently which made me think we were subject to some good ol' fashioned postal theft. We do live on a busy street. . . Mystery one: Erin didn't receive a Valentine's card from my parents Mystery two: Erin and Robin didn't receive a message from Grandma and Grandpa from Hawaii. Mystery three: an old class-mate said she was sending a package ... which has never appeared. Concurrently, I'd read recently about some mail thefts in our area. So I started to lock the mailbox. Then the belated Valentin's arrived. The postal sorting mis-read the zip code. The Hawaiian message arrived at Grandpa and Grandma's house with postage due. The item from my old classmate is still not here, but I"m starting to think it has more to do with strangely coinciding system glitches and not nefarious neighbors pilfering our greeting cards.