How Strange!

I just nipped down to my local Brit newsagent to see if I had any post. I use Offex which is like a courier service. We've tried Spanish post and some of our mail has taken 6 months or more, so now I have a PO Box Number at the newsagents.

The sender addresses the post to the Offex PO Box at Gatwick Airport where its put on a domestic flight to Malaga and is then sorted and distributed.

The gentleman at the newsagents said their post is absolutely normal. Incoming and Outgoing. Now, if they can do that with mail, can't they put a few passengers on there too?