Unclear of the concept

I sent a message to the school's mail email address this morning to inform the secretaries of something, and it came back as underliverable (Yes, I verified that I had sent it to the right address). When I got to school, I told Young Secretary about the email bouncing. She said that the mailbox might be full, because they get a lot of email with virus attachments that take up space. I asked her if she thought she should clean out the box in case something important came in (perhaps a contract for more business). Her response was, "Why? Then more of the spam email will come in and I'll have to clean it out again."

I walked away.