How to change your email password on your iPhone
1) First, locate and press the “Settings” icon.
2) Then select “Mail, Contacts, Calendars”.
3) Select the email account for which you want to update the password.
4) Then select the email account. This is where you can update your email password. You should only have to do this if your email password has changed.
5) Enter your new password.
6) When finished, press “Done”.