Exchange 2003 Reached 16 GB Mailbox Store Limit

I received a report that users of a Microsoft Exchange 2003 server, which is running on a Windows Small Business Server (SBS) 2003 system, could not send email nor access shared calendars or contacts lists. When I connected to a user's system, I found Outlook was showing it was operating disconnected from the Exchange server. When I attempted to send email from Outlook, I received an error message.

Microsoft Office Outlook
The connection to the Microsoft Exchange Server is unavailable. Outlook must be online or connected to complete this action.

[ OK ]

I also saw the message below:

Outlook Send/Receive Progress
Task 'Microsoft Exchange Server' reported error (0x8004011D) : 'The server is not available. Contact your administrator if this condition persists.'

When I examined the application event log on the Exchange server, I saw the following entry listed:

Event Type:	Error
Event Source:	MSExchangeSA
Event Category:	MAPI Session 
Event ID:	9175
Date:		5/1/2006
Time:		12:35:52 PM
User:		N/A
Computer:	S
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 

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I did not see an immediate cause for the problem. Rebooting a client workstation did not resolve the problem, nor did rebooting the server.

Checking on the event log entry, I found the following advice from Microsoft for troubleshooting the problem:

Product: Exchange 
Event ID: 9175 
Source: MSExchangeSA 
Version: 6.5.0000.0 
Message: The MAPI call 'value' failed with the following error:

error code 
This Error can be triggered under a variety of conditions:

When mounting a mailbox store or public folder store. 
When the System Attendant is trying to generate an Offline Address Book. 
When the stores are down and the SA is trying to do its routine management tasks. 
When attempting to perform a Move Mailbox operation. 
At the rate of 1 every minute on a Clustered Exchange Server. 
In essence, this message indicates that the System Attendant process has been unable to log on to the Mailbox Store or Public Store.

There are several flavors of this event. The ID number in the Description section of the event will be the only difference between the events. Depending on what the underlying cause of the problem is, the ID number will vary. The other ID numbers that might be seen are: 8004011d-0519-0000000, 80040111-0286-00000000, 8004011d-0289-00000000

There could be several causes for this event, but the main ones to look for are:

Information Store (IS) is not running. 
IS is running, but one or more databases are not mounted. 
The Read System Access Control List (SACL) of Exchange Enterprise Group is lost. 
Inappropriate permissions on the MDBDATA folder 
System Attendant Service is running with a different user account than "Local System". 
The Default Public Store attribute on an Exchange 2000 server points to an Exchange 5.5 server public store in another domain 
The System Mailbox object that is created for this mailbox store exists in the Microsoft Exchange System Objects container 
User Action 
While the proper resolution will be determined by the ID number that shows up in the event, you can try the following actions:

Verify that the Information Store is running. 
Make sure that the default mailbox store is mounted. 
Run setup /domainprep. 
Verify the permissions on the MDBDATA folder. 
Change the properties of the System Attendant Service so it runs in the context of the Local System Account. 

After a lot of checking I found the problem was caused by the Exchange database store reaching the 16 GB limit1 inherent in Exchange Server 2003. The default limit was increased with Service Pack 2 to 18 GB and can, through a registry setting, be increased to 75 GB2.

The relevant file is priv1.edb, which will by default be located in C:\Program Files\Exchsrvr\MDBDATA. It is possible to move the location to another directory, though, so on some systems it is possible the file has been moved elsewhere. If that file is 16GB, then the file's size is likely the source of the problem.

To resolve the issue, you need to install Exchange Server 2003 Service Pack 2. But I found the following in the Microsoft Exchange Server 2003 Service Pack 2 Release Notes.

Make sure that you install the following hotfix before you install Exchange Server 2003 SP2.

Ensure that Hotfix 898060, " Installing security update MS05-019 or Windows Server 2003 Service Pack 1 may cause network connectivity between clients and servers to fail" has been installed on your system. You can determine whether this hotfix is installed by running the Microsoft Exchange Server Best Practices Analyzer Tool, which checks for the hotfix being installed, and then reviewing the output log. If you do not run the Exchange Server Best Practices Analyzer, you must manually verify that Hotfix 898060 is installed on your system. If this hotfix is not on your system, you must install it now. This hotfix is applicable only to Windows Server 2003 customers who applied security update MS05019 or Windows Server 2003 SP1.

I was able to resolve the problem by installing the hotfix mentioned above and then Exchange Server 2003 Service Pack 2.


  1. Exchange Server 2003 mailbox store does not mount when the mailbox store database reaches the 16-GB limit
    Microsoft Help and Support
    April 30, 2006
  2. How to increase the Exchange Server 2003 Service Pack 2 18-gigabyte database size limit
    Microsoft Help and Support
    January 20, 2006
  3. Exchange Server 2003 Service Pack 2
    Microsoft Download Center
    October 19, 2005
  4. Windows Small Business Server 2003 Service Pack 1 Windows Small Business Server 2003 Home
    Updated: June 6, 2005
  5. Microsoft Exchange Server 2003 Service Pack 2 Release Notes
    March 16, 2006
  6. Windows Server 2003 Service Pack 1 Preview
    Paul Thurott's SuperSite for Windows: It's the future of Windows...Today!
    Updated: February 23, 2005
  7. Downloading and Installing Windows Small Business Server 2003 Service Pack 1
    Microsoft Download Center