To change your password on your phone's exchange account please follow these steps:

For iPhone Only:

1. Click on the settings icon on the phone

2. Select "Mail" in the settings list

3. Select "Accounts" (This should be the fourth option)

4. Select your work/exchange/lerchearly/leb account

5. You will be prompted to put in your new password. 

For Android Only:

1. On the Android device, tap Settings.
2. Under the Personal heading, tap Accounts.
3. Tap Exchange.
4. Tap Account Settings.
5. Tap the account for which you would like to update the password.
6. Scroll all the way down and tap on Incoming Settings.
7. Update your password and tap Done.

Your email should work properly on your phone again