Microsoft Outlook 2007-2013 support American National Standards Institute (ANSI) and UNICODE personal folders (.pst) and offline folder (.ost) files. The WarnFileSize registry entry determines the maximum data that both the .pst and the .ost files can have. After this maximum data is reached, neither the .pst nor the .ost files are permitted to add any more data. These limits can be changed per user in the registry:
The files can be found in: %LOCALAPPDATA%\Microsoft\Outlook
- Open HKEY_CURRENT_USER>Software>Policies>Microsoft>Office.
- Expand 11.0 for Outlook 2003, 12.0 for Outlook 2007, or 14.0 for Outlook 2010, or 15.0 for Outlook 2013, and then expand Outlook.
- Click PST, and then right-click MaxFileSize in the right pane.
- Click Modify, and then type the value in the Value data box.
- Click OK.
- Right-click WarnFileSize, and repeat steps 8 through 9.
- Right-click MaxLargeFileSize, and repeat steps 8 through 9.
- Right-click WarnLargeFileSize, and repeat steps 8 through 9.
http://support.microsoft.com/kb/832925/en-us
Outlook 2013 and Outlook 2010
| Name | Type | Valid Data Range | Default |
|---|---|---|---|
| MaxLargeFileSize | REG_DWORD | 0x00000001 – 0x0000C800 | 0x0000C800 51,200 (50 GB) |
| WarnLargeFileSize | REG_DWORD | 0x00000000 – 0x0000BE00 | 0x0000BE00 48,640 (47.5 GB) |
| MaxFileSize | REG_DWORD | 0x001F4400 – 0x7C004400 | 0x7BB04400 2,075,149,312 (1.933 GB) |
| WarnFileSize | REG_DWORD | 0x00042400 – 0x7C004400 | 0x74404400 1,950,368,768 (1.816 GB) |
Outlook 2007 and Outlook 2003
| Name | Type | Valid Data Range | Default |
|---|---|---|---|
| MaxLargeFileSize | REG_DWORD | 0x00000001 – 0x0000C800 | 0x00005000 20,480 (20 GB) |
| WarnLargeFileSize | REG_DWORD | 0x00000000 – 0x0000BE00 | 0x00004C00 19,456 (19 GB) |
| MaxFileSize | REG_DWORD | 0x001F4400 – 0x7C004400 | 0x7BB04400 2,075,149,312 (1.933 GB) |
| WarnFileSize | REG_DWORD | 0x00042400 – 0x7C004400 | 0x74404400 1,950,368,768 (1.816 GB) |