Mac Mail unable to delete old emails in inbox. Any ideas how to fix this? I am using exchage.

I recently got a new macbook pro and I have set up my work exchange email account to the computer for email. It work great except for the fact that I have these old emails that came over from my exchange account that when I try to delete them, I get this message telling me that the mail could not be moved to the trash. Any new email goes to the trash just fine when I delete it. Any suggestions on how to fix this? Also, when you log into our server these old messages that are on my mac are not on the exchange server.