This may seem like a nit but these are the kinds of things that make the Mac a Mac, intuitive and interesting.
In 10.9 Preference/Viewing Smart Addresses meant if the user has only one Email show only the Name, else if the user has multiple Email addresses show the Name and Email being used in this instance of send, read or whatever.
In 10.10 Smart Addresses only show Name or Name and Email.
Thats not so Smart, the button should be "Show Name Only" if that was the case.
I certainly hope this is a bug.
In 10.9 Preference/Viewing Smart Addresses meant if the user has only one Email show only the Name, else if the user has multiple Email addresses show the Name and Email being used in this instance of send, read or whatever.
In 10.10 Smart Addresses only show Name or Name and Email.
Thats not so Smart, the button should be "Show Name Only" if that was the case.
I certainly hope this is a bug.