Some mornings (not all) we get several users complain that outlook it asking to provide credentials (this is almost a daily issue but the user effected changes)
some times just leaving the account for a few minuets (20 or so) will then allow the accounts to log in again.
Also if we get the effected user to log into OWA outlook seems to burst back into life again.
I think we have ruled out client issues as it has happened at least once or twice to every user member (about 120 users)
OWA always works though.
Has any one seen this before or have any idea what could be causing this. I have my own suspicions but whant to know what people think first.