When your password changes at work this also effects your email on your iPhone or iPad. You will notice that your emails stop syncing. In order to update your password, please see the below steps:
1. Tap on the 'settings app'
2. Scroll down and tap on the 'Mail App'
3. Tap on Accounts
4. Tap on the account you are wanting to update the password for
5. Tap on the Account
6. Tap on the password field. Remove the password and then update it with the password that has recently been changed on your work PC. Once updated, tap done.