Does apple Mail app automatically delete "old" emails?

I just tried to find an "old" email in my inbox and/or smart folder(s) and I found that no emails older than two months old are there. Have they been automatically archived somewhere? I have checked all the Mail preferences and there are none that address the INBOX or SMART MAILBOX behaviors. This is a disaster! If this can't be fixed I've got to quit using this app last year!