In the Conversation Inbox, there are set file types that can be attached, even when uploading them. This makes no sense. We are a software company where we send "license files" and customer configurations (think of ini files) to our clients. Most all of the reservice requests we get involve one of these two tsks. Because the file formats are specific to our application. We cannot send these via the conversations Inbox. We can reply to a ticket however, but this is now contrary to the idea of how an inbox functions in a team enviroment.
These attachments are mostly text files, or non-executable bianary files. So it isn't a security concern. It just seems like an artificial limitation. I can see blocking .exe or .pst files. However you allow .mov files and .wav files which from a security standpoint are much more common to include malware.