Dropped Off Packages In Mailboxes

Dropped off three packages yesterday at the mailbox right outside my local post office, and I wasn’t aware of this problem until like five minutes ago. Has anyone else dealt with this? What do I do? Visit my post office? Or will they just send it back via return address?

Dropped off three packages yesterday at the mailbox right outside my local post office, and I wasn’t aware of this problem until like five minutes ago. Has anyone else dealt with this? What do I do? Visit my post office? Or will they just send it back via return address?