Prevent auto attach email to case

Hi,

We have dynamics 2011 and noticing that all emails we are receiving with a specific title and from the same email address are being associated with an existing case. I can see why it is doing this but we would not like this to happen if emails come from a specific email address. Is there anyway we could do this, either through workflows or some other settings?

Or perhaps is this only available in later versions of CRM?

Thanks,

Richard