You can remove email accounts: Tools, Accounts, select the account,
then click Remove.
Any folders that *you* created you should be able to right-click on,
and one of the options will be Delete. It is not possible to delete
folders that were created by Windows Mail.
You cannot completely remove the email portion of Windows Mail.
It is considered to be part of the operating system, and as such,
those files are protected from deletion.