The easiest way is to remove it on your provider's BIS (BlackBerry Internet Service) web site.
Links to all North American provider's BIS sites is at the bottom of this page: http://na.blackberry.com/eng/support/software/internet.jsp;jsessionid=497591238CEF29C1CB072FCFEB 8BC1FD
If you have an item on your BlackBerry's main screen named Personal Email Setup
, you can do it from there too (it will actually just bring you to the BIS site).
You may also want to delete the associated Service Book. On the BlackBerry go to (Settings/Tools -->
) Options --> Advanced Options --> Service Books
. Highlight the entry with the email address you want to get rid of followed by [CMIME]
the wheel or menu button and select Delete
Note that just deleting the service book will NOT stop the email. Once the association is established, emails are sent to the PIN unless the service is removed from the back end. I once wiped my BB and still kept receiving my BIS email even though I didn't have the service books.