Dealing with email attachments

We are looking for a solution to attachments coming into our email server, exchange 2010. Aside from the strain it puts on the server, we want to find a way to prevent people from blindly opening attachments, specifically the few spam ones that slip through.

We have pondered blocking all attachments and forcing senders to send attachments to an FTP/Dropbox account. We have thought about adding a disclaimer on incoming attachment mail.. We wanted to have a prompt popup on user PCs before opening attachments within outlook but couldn't seem to find anything that would work that way.. in exchange or outlook.

We are curious if other people handle attachments differently or if there are any feasible solutions. Our end goal is to do what we can regards to blindly opening attachments.