Owners of Microsoft Small Business Server 2003 have often complained that the Exchange server hard limits the mail store size to 16GB. These days – 16GB of email isn’t that much – especially when you have many users.
However, this limit is not actually a hard limit. You can in fact increase the mail store up to 75GB, very easily. You won’t even have to do a reboot.
Here’s how:
Step 1.
Download and install the Exchange 2003 Service pack 2. You can download it from here: http://www.microsoft.com/downloads/details.aspx?FamilyID=535bef85-3096-45f8-aa43-60f1f58b3c40&displaylang=en
Step 2.
Open your prefered registry editor. For example:
Start > run > regedit.
Step 3.
Find the following registry keys.
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeIS\{Your Server name}\Private-Mailbox Store GUID
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeIS\{Your Server name}\Public-Public Store GUID
Step 4.
Add these new DWORDS to both of those keys;
DWORD: Database Size Limit in Gb
Value: Between 1 and 75 (in decimal)
(This is the mailstore size)
DWORD: Database Size Buffer in Percentage
Value: Between 1 and 100
(This is the % free at which warnings will start. 10% is fine).
DWORD: Database Size Check Start Time in Hours From Midnight
Value: Between 0 and 23
(This is the time of day the mailstore will be size checked. Do it off peak).
Step 5.
Restart your Exchange services. If you view the Application logs, you should see the mail size has now increased from 16GB to whatever value you used.
