This article was previously published under Q197430
In Microsoft Outlook, a feature, "Allow upgrade to large tables," is available for personal folder (.pst) files. This feature increases the limit on the number of folders per file and the number of messages per folder in a .pst file. The limit has been increased from approximately 16,000 folders per file and approximately 64,000 messages per folder.
Selecting this personal folders option causes the headers of the .pst file to be permanently updated.
NOTE: Earlier versions of Microsoft Exchange and Outlook may be able to access a .pst file that has been updated to allow the large table format. However, this is not supported and may cause instability and corruption in the .pst file.
The procedures for getting to the properties of your personal folders are different for the Corporate Workgroup (CW) and the Internet Mail Only (IMO) installations of Outlook. To make the "Allow Upgrade to Large Tables" feature available, refer to the appropriate section below for instructions.
Making "Allow Upgrade to Large Tables" Available (CW)
To make this feature available in Outlook (CW), follow these steps:
On the Tools menu, click Services.
Click to select the Personal Folders service, and click Properties.
On the General tab, click to select the "Allow upgrade to large tables" check box.
Making "Allow Upgrade to Large Tables" Available (IMO)
To make this feature available in Outlook (IMO), follow these steps:
In the Folders list, right-click Personal Folders, and click "Properties for Personal Folders" on the shortcut menu.
On the General tab, click Advanced.
Click to select the "Allow upgrade to large tables" check box.
Click OK and OK.
16383 16,383 16384 65535 65,535 65536 thousand maximum