It would be nice to be able to select which, of multiple email accounts, to view in the Mail Message list widget.
At the moment the default is the "Unified Inbox"
This could be shown as "< Unified Inbox >" with a tap on < or > the changing to "< Account one >, "< Account two >, etc. rotating backwards or forwards through the accounts.
An example of this can be seen in the equivalent Samsung mail widget.