Just setup an email address attached to an Exchange public folder. So incoming emails can be shared between several people but it also acts as a master list, that way you can see what has been actioned already.
You can also add the Send As permission in the Active Directory for that folder, so staff can change the email address that the message is sent from. You then need to enable the From field in the new message box. Also make sure the address is visible in the global address list and not hidden.
We noticed that incoming emails stored in the public folder didn't show the email distribution if anyone had been cc'd in. This was tracked down to the format being IPM.Post not IPM.Note. You can add a registry setting to force all new emails to store as Note, and therefore display the email distribution:
"Incoming defaults to IPM.Note"=dword:00000001
Restart the Exchange Info Store.