One user's mailbox size was set to 200,000KB. User requested to raise it to 400,000 KB. A jr admin set it to 400 KB, by mistake. Now the user is not able to send or receive mails. I reconfigured it to 400,000 KB and then to 450,000 KB. But still the user is not able to send and receive mails. Even can't access OWA.