Sharepoint doc library files are being marked as edited when opened

I have several libraries where this is happening.  Sometimes, the files are Word and Excel, and probably has to do with AutoSave or some similar setting.  Sometimes, though, it's with email messages that I know are only being viewed.  

There's also instances where it states that I edited the email file about 20+ times in a single day.  I'm pretty sure that it most cases, I didn't even open it, and if I did, it would have been once.

Anyone know why this is happening? Thanks