When I was young a mail box meant a box where you received your mail from the US Post office. Mail boxes today have numerous meanings. It could be the message queue where you receive your electronic mail. It could also mean the teacher’s mail box of the pigeon hole variety. Another type of mail box is the voice mail box for your telephone. Of course, we still use the meaning for a letter holder on your desk. While most people think of a mail box as receiving incoming mail, mail boxes also come in the outgoing variety. So, you need to think twice when someone says the word, mailbox!