Question : Exchange MBX missing

We are having an issue with Exchange.
Geting errors:
Event 445
Information Store (3100) The database D:\Program Files\Exchsrvr\mdbdata\priv1.edb has reached its maximum size of 16383 MB. If the database cannot be restarted, an offline defragmentation may be performed to reduce its size.
Event: 9175
The MAPI call 'OpenMsgStore' failed with the following error:
The attempt to log on to the Microsoft Exchange Server computer has failed.
The MAPI provider failed.
Microsoft Exchange Server Information Store
ID no: 8004011d-0512-00000000

The interesting thing is the MBX folder has dissapeared? Folder should be located under M:\\MBX
We are able to start the infomation store but it only stays up for a short time?

Any help is appreciated.
Thanks

Answer : Exchange MBX missing

well have you mounted the database? you won't see anything there is the database isn't mounted...