[penguin3107]

You don't remove the Enterprise Activation screen. Just ignore it.

In OS 5 and prior, the BIS email setup icon you're looking for is in the 'Setup' folder.
It's called 'Email Setup' or 'Personal Email Setup' or something along those lines.

If you're running OS 6, then in the Setup folder is an option called 'Email Accounts'.
When you choose that, one of the options should be 'Internet Mail Account'