On my S3 I had it set to vibrate once for email and twice for messaging. Can this be done on the S6, I cannot find a setting for that.
I see that the S6 does allow a variety of vibration patterns, though it seems to cover all notifications once you set it to something. Perhaps there's an app that will let you assign the patterns to different notifications?
Light Flow Lite - LED Control - Android Apps on Google Play is one I have used in the past for custom LED colors, but it also allows vibration patterns according to the write up. It might be worth checking out...