I have a user who cannot send or receive email. Emails sent to his mailbox come back with a 5.2.2 warning: "the message could not be delivered because the recipient's mailbox is full." (The server is Exchange 2003 and clients are all using Outlook 2003.) Yes, there are quotas enabled, but the mailbox is definitely well below them. I have confirmed this in both the Exchange System Manager console, as well as looking at the Mailbox properties in the user's Outlook client.
Emails sent to the user are being bounced with the 5.2.2 warning whether sent internally within the business LAN, or coming through our SMTP gateway using an external browser mail client. For what it's worth, I also tried increasing the user's individual quota through AD User's and Computers, then rebooting the Exchange server forcing AD replication. But I'm still getting the same 5.2.2 warning. I'm really stumped at this point and could use any ideas. Thanks in advance.