Post office

So my Sneek Peek test came in today and I really want to get it done as soon as possible. My problem is that I leave town to go to work right as the post office opens in the morning and do not get back home until the post office closes. Now I was wondering if it would matter if the package was sent to my address but I send it back out at a different post office in the town I work in? Can I do that? The test says to take it to the actual post office and not in the mailbox.