Open the Settings app on your iPhone
Tap Mail
Tap Accounts
Select the email account you want to update
Tap Account
Tap Password
Enter your new email password
Tap Done or Save
If prompted, sign in again with the updated password
If the password field is not available, update the password through your email provider’s website first
Return to Settings and re-enter the updated password in the account settings
If needed, delete and re-add the email account with the new password