1.
Try this:
- Go to manage applications under settings,
- Find the email app
- Press the clear data and clear cache buttons
- good chance that this will stop the error messages to appear.
- Start up the Email app
- if you still see your (new) work account: delete it
- good chance that this will fix it happening again.
2.
If the ICS upgrade is rolled out, there will be the option to disable pre-installed apps.
3.
If you don't get the email app to connect to your account,
a simple alternative is to use your webmail interface, bookmark that site in the web browser,
and place that bookmark somewhere on your homescreens, similar as you would place an app-icon or a widget.