Delete email account on iPod touch

From Chapter 18 of the iPod Touch Users Guide:

Delete an account from iPod touch: Choose “Mail, Contacts, Calendars,” choose an account, then scroll down and tap Delete Account.

Deleting an account means you can no longer access the account with your iPod touch. All email and the contacts, calendar, and bookmark information synced with the account are removed from iPod touch. However, deleting an account doesn’t remove the account or its associated information from your computer.