With all icons visible, look around your home screen for any and all e-mail-inbox icons. You should see the main "Messages" inbox, along with icons for every BIS, or Web mail, account. And if you're running a recent OS 5.0 build and/or the option is enabled on your BES, you'll see a BES icon, called something like "Desktop" or whatever you've assigned as a label for your corporate mailbox.

Your mail is already separated if you see the BES icon--it has a small "briefcase" at its base, as opposed to the BIS icon, which has a small globe. Ensure that none of the individual mail-inboxes is "hidden"--hidden icons are "shadowed" or more lightly colored than visible icons. If one icon is hidden, scroll over it, hit your Menu key again and uncheck the "Hide" option.

When no e-mail inbox icons are hidden, click Menu one last time and uncheck "Show All." You may also want to hide your main Messages inbox, since you'll already have separate inboxes for all accounts.

I prefer to use a "Today" theme that has fixed "Messages" and "Calendar" sections on the Today screen, so I can access the Messages folder from there, even though I have it hidden on the Home screen. And I keep separate inboxes for all my mail accounts on that Home screen for quick access to specific mail. ( for the Bold 9700 is one example of such a theme, and it's also the theme pictured in this post.)