When you get a lot of mail, does the mailman have to stuff it all into the box on that day?

The magazine I subscribe to came in the mail today, but also had many other pieces of mail. So the mailman just stuffed it in the mailbox, and when I took it out it was all creased and bent and deformed. I’m really not that upset about it, but I can understand someone getting upset at receiving a magazine they pay for in such a poor condition. This brings up an interesting dilema, what if you happen to receive an enormous amount of mail one day, so much that it can’t all fit inside the mailbox, will the mailman have to keep it until the next delivery day?