Maybe I am unusual inso far as I work with around 20+ emails (no I am not a spammer) for various business requirements and hosting websites.
I would love to be able to, after setting up accounts that belong to the same mail server, group these accounts using a visible separator within the account list under the left coloumn. For me it is the server that is the first point of reference and then the name. As I use my own name across the majority of the servers it would make life much simpler for me - and perhaps for someone in a similar environment.
Hopefully this is not such a biggie.