Convert OST to PST
OST File Size Configuration in Outlook 2010 and 2013
Offline Outlook Data Files (OST) of MS Outlook allows users to work offline (in Cached Exchange Mode) when Exchange Server connectivity is not there. It is actually a local copy of Exchange Server mailbox. But sometimes Outlook users may find it difficult to work with OST files, especially when they become corrupt in some way. One of the problems faced by OST is the growth of its file size. When Outlook file grows beyond a certain limit, they become inaccessible.
The maximum size that can have for an Outlook Data File (OST or PST) is different for different versions of Outlook. In earlier versions of Outlook (Outlook 2002 and earlier versions), this size limit was very small (2GB) as they supported only American National Standards Institute (ANSI) format. But Outlook 2003 and later versions supports UNICODE format (this is the default format) as well. So the maximum size possible for OST (or PST) is greater in them. In Outlook 2003 and 2007, the default size limit is 20 GB where as in Outlook 2010 and 2013, it is 50 GB. However, in all UNICODE supporting Outlook versions, you can configure the OST (or PST) file size according to your convenience. It helps you minimize OST corruption that arises due to the size limitation of the OST.
It is possible to the set a size limit for OST or PST files in all Outlook versions that support UNICODE format. This is by configuring the following registry entries of Outlook:
- The MaxFileSize registry entry
- The WarnFileSize registry entry
- The MaxLargeFileSize registry entry
- The WarnLargeFileSize registry entry
The MaxFileSize registry entry & The MaxLargeFileSize registry entry
This is the maximum size possible for OST or PST file. Outlook does not allow file size to grow beyond this limit.
Note: here, The MaxFileSize registry entry refers to an ANSI formatted file and The MaxLargeFileSize registry entry refers to a UNICODE formatted file.
The WarnFileSize registry entry & The WarnLargeFileSize registry entry
This indicates the maximum data, the OST or PST file can have. Outlook does not allow adding data after this limit is reached.
Note: Here, The MaxLargeFileSize registry entry refers an ANSI formatted file and The WarnLargeFileSize registry entry refers to a UNICODE formatted file.
For Outlook 2010 and 2013, you can follow the steps below to configure the OST or PST file size.
1. Go to C:\WINDOWS and open Registry Editor (regedit).
Note: You can open Registry Editor as below also:
Windows XP - Open Run, type Regedit and press Enter.
Windows 7/Vista - Click Start, click Search, type regedit and press Enter.
Windows 8 - Right-click on the bottom-left, select Run, type Regedit and press Enter.
2. In the left pane, expand My Computer.
3. Go to (detailed steps are given in the note just below):
HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\15.0\Outlook\PST (For Outlook 2013)
HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\14.0\Outlook\PST (For Outlook 2010)
Note: Expand HKEY_CURRENT_USER; expand Software; expand Policies; expand Microsoft; expand Office; expand 15.0 (for Outlook 2013)/14.0 (for Outlook 2010); expand Outlook; finally click PST.
4. In the right-pane look for:
Note: If these registry values do not exist, you will have to create them.
5. Right-click on MaxFileSize; click Modify; enter the value in the Value data box; click OK.
6. Repeat the step 5 for:
7. Finally, close Registry Editor.
Note: These settings apply to both OST and PST files.
A word of caution before starting: Please follow the steps carefully and modify the registries accurately. Otherwise, it may lead to serious errors. You are recommended to back up the registry before modifying, (so that you can restore it if some error occurs).
When OST files becomes corrupt, some third-party tools like Kernel for OST to PST helps you access corrupt or inaccessible OST files by converting them to PST. When the Exchange Server becomes corrupt, or the user account is deleted, Kernel for OST to PST provides an excellent means to access emails, contacts, journals, calendars, notes, drafts and other Outlook items very quickly. Compared to the inbuilt Microsoft tools, Kernel for OST to PST is quick, comprehensive and user-friendly.
- Resolves major as well as minor OST corruption issues.
- Recovers Outlook data from compressed and password protected OST files.
- Performs OST to PST conversion even if the OST file large
- Has the facility to search for emails and the facility to filter emails by date range
- Allows to save the repaired OST in PST, DBX, MSG, or EML format
- Supports even the latest versions of MS Exchange Server and Outlook
- Available as free trial version
Before purchasing Kernel for OST to PST, you are recommended to use its free trial version. The trial version lets you evaluate its OST to PST conversion features and performance by previewing the repaired items. However, you need to purchase the software in order to save the repaired items.