Internal Server Error User ‘username’ is over quota

One of our client account was over quota and he cannot access cPanel and Webmail,then we have update the package now he can access cPanel but when try to login Webmail it still display error :

Internal Server Error

User 'useraccount' is over quota.

In this post we will show you how to fix this error.
First Go to WHM->tweak settings, disable all Webmails and save
then enable them again.
Second SSH into your server and run the following commands:

cd /var/cpanel/overquota
rm -f username

Make sure to replace the Username with the exact cPanel username .
If still not working  you may try using:

/scripts/upcp --force

 The error should be disappear now.