Mail problem following update 9.0.2

Since updating our iPads (16gb & 128gb) we cannot access or use our email account!

when trying to collect & update mail it suggests that out password is incorrect - which it is not. It suggests that we go to setting & re-enter our password. Now it tells us we have a mismatch!

We have tried changing the password but the result is always the same.

The only way we have managed to get our mail has been to download the Yahoo Mail app which works perfectly ok with our password.

However we would prefer to revert to the usual iPad mail functions.

Any ideas?