Outlook freezing

On site we have a number of people who run the quantlet with their e-mail a/c’s i.e. if they have a 20mb mailbox they use 99.9% of it.

By default our exchange server notifes the user that there a/c is running out of space,but when the user gets the alert message it freezes out there a/c and they need to restart their outlook.

To make matters worse if they then scroll to message they have recieved about there e-mail a/c running out of space it freezes there a/c again.

Only solution i have found is to log in to their a/c as a delagate and delete the message.

Any suggestion?