I’m sure there are a lot of people out there who buy hundreds of things from the AH each day. Now this sucks really bad when you have to retrieve the items out of your mailbox one-by-one… This is where this addon comes into play and has saved me hours of time! It’s called CTMail Mod . What it does is add 2 extra buttons at the top of your mailbox screen, simply click the "Open All" button and all the items will magically pop into your bags 
Hope this mod saves you a lot of time!