freitasm: I have two mail accounts... On my HTC One I have two homescreen shortcuts, going directly to each account, showing different unread counters. IIRC when I created a Mail shortcut it asked which account to show. This doesn't seem to work on the samsung S5?
Haven't used Samsung's email app in a while, but on S III/Note II-era Touchwiz, there was an option in the widget menu (Long press multitasking on the S5 or long press on an empty homescreen area, then tap widgets) to add individual email account icons with badge counters. Doesn't seem to be there on my Note 3, although I don't have any accounts set up in Samsung email.
I quite dig Samsung's badge counters, particularly the way Facebook has embraced the badge counter API for the Facebook & Messenger apps. Twitter did as well, though it never seemed to work reliably.



