We have just recently restored our Exchange server from a backup, and we can access all old email in the system, but any new email received gets a "Cannot open this item, Unknown Error" message. If we access the mail using OWA, we get a HTTP 500 Error, and if a client tries to access via POP3 or IMAP, this is generated in the event viewer:
Error 0x800ffff occurred while rendering message 001c-00000004d508 for download for user *@*.com
I've run ISINTEG /fix, and used ESEUTIL to check the database consistancy, but still not been able to fix the problem. All old email can be accessed, but no new emails.
Can anyone help?