Microsoft Outlook limits the size of older Personal Folders .pst files and offline folders .ost files to 2GB. If a new or changed item increases the size over than limit, you will not be able to use the .pst or .ost file. Even if you delete items from the server mailbox, the .ost file will not synchronize.
Beginning with Outlook 2003, larger PST files are supported. However, if you upgrade from an older version you need to create a new PST, the older PST format is not automatically converted or upgraded. See Convert an old PST to a Unicode PST. If the old PST won't open in Outlook you will need to repair it before you can convert it.
Shrinking a file that’s over the limit | Preventing files from growing too large | Other Tools | More information
How to check the data file (pst) format
Right click on the top level folder and choose Properties (Data File Properties in Outlook 2010)
Click Advanced to open the data file dialog.
If the data file is listed as “Outlook Data File” and you are using Outlook 2003 and up, its a Unicode data file.
If the data files is called “Outlook 97-2002 Data File” its an older ANSI format and is limited to no more than 1.9 GB in size and no more than 65,000 items per folder (often less).
Shrinking a file that’s over the limit
Outlook has no built-in way to reduce a PST or OST file that has gone over the limit. However, Microsoft provides a tool, PST2GB, which you can download to restore the file to operability. Note, however, that the utility truncates the data from between 25 and 50mb and the truncated data is not recoverable. The remaining data under 2GB should be restored. See OL: Oversized PST and OST Crop Tool for more information.
If you want to attempt repairs yourself, use a tool called a hex editor to edit the data in the file directly. Every Windows shareware site has a selection of hex editors. Eugene McCarthy of FAO Headquarters in Rome recommends the free iHex editor, which loads only 64kb of the file at a time, making it ideal for tinkering with extremely large PST files.
Make a backup of your PST or OST, then open the original file with the hex editor (available for download from any Windows shareware site). You’ll want to remove a few characters from the middle of the file, then save it and try to run the Inbox Repair Tool (Scanpst.exe) to repair the damage you did with the hex editor. If Scanpst can repair the file, you should be able to open it Outlook again. If not, try removing some additional characters from the file.
If this process works, with any luck, you’ll lose only one or two items. You may be able to recover 100% of the data by repeating the process with a new copy of the file, but removing the data from a different area.
Preventing PST files from growing too large
Beginning with Microsoft Office XP Service Pack 1, Outlook provides better protection against Personal Folders .pst and offline folders .ost file growing past the 2GB size limit. Once an PST or OST file reaches 1.82GB, users will not be able to add new items. See:
- Mail Delivery to Inbox Stops When the Personal Folder or Offline Folder Is Full
- Error Message Copying File to PST That Exceeds 1.82 GB
Office 2000 Service Release 1/1a updates Outlook 2000 so that you cannot add more data as the PST or OST size approaches 2GB; this prevents corruption, but the user gets no warning.
| Tools in the Spotlight | |
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Advanced Outlook Repair (AOR) is a powerful tool to repair and recover corrupted Outlook PST files. Main features: recover mail messages, folders, posts, appointments, meeting requests, contacts, distribution lists, tasks, task requests, journals and notes in PST files; support to recover attachments; support to recover deleted Outlook items; support to recover oversized 2GB PST files; support to split the output PST file into several small ones; support to recover password protected PST files; support to convert PST file from Outlook 97-2002 format into Outlook 2003/2007 format. Version 3.2 Full support for Outlook 2010. | |
Kernel for Outlook PST Repair Tool recovers and restores emails and other items from damaged, corrupted or broken PST files. A demo version is available and shows you exactly that how many emails and other items will be recovered using the full Kernel Repair PST Software. Kernel for Outlook PST Repair supported versions are Outlook 97, 2000, XP, 2003. It successfully recovers all items from the PST file including emails, drafts, calendars, journal, notes, tasks, contacts etc. OST repair tool also available. | |
Outlook Recovery locates Microsoft Outlook files and databases automatically no matter what disk or storage device has been used to keep them. If you experienced a hard drive failure or deleted an Outlook database by an accident, Outlook Recovery will perform a full scan of that disk in order to locate and undelete/recover the database. If a database is corrupted, Outlook Recovery will repair it so that it can be used with Microsoft Outlook again. Outlook Recovery can recover Outlook databases in PST and OST formats, saving them for using with Microsoft Outlook, Outlook Express, or any email application that supports the EML format. | |
Outlook PST Repair software is developed to repair the corrupted PST file and for recovering its entire mailbox items. This software even repairs file which are larger than 2 GB and also recovers deleted emails. Stellar Phoenix Outlook PST Repair software has several powerful features like repair password protected and encrypted files and also recovery of selected folders. This software works with almost all latest Outlook versions and has good compatibility with Windows 8, 7, vista, 2003, 2002 and 2000. | |
| Tools | |
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CopyPST repairs Outlook data files by exporting it to a new file, ignoring any error. It requires that the data file can still be opened in Outlook. Exporting a file breaks links, which can be repairs using OLfix program. Free | |
Disk Doctors Outlook Mail Recovery (.pst) efficiently recovers messages, folders, appointments, meeting requests, contacts, tasks, task requests, journals and notes from .pst files. Mails are recovered in plain text, HTML and RTF format. The software has advanced support to recover large attachments and embedded HTML messages. It also supports recovery of password protected .pst files and both compressed encryption and high encryption .pst files. The software creates a new healthy .pst file from a corrupt .pst file. | |
The software enables the recovery of deleted messages and messages from corrupted Microsoft Outlook and Microsoft Outlook Express data files. Messages, attached files, contacts and notes can be viewed, saved in the EML/VCF/TXT format and later imported into the mail client. The program uses original algorithms that assist in the recovery of a maximum number of messages even if the mail client cannot open the message database. | |
Repair corrupted .pst and .ost files and those exceeding the 2gb limit. Retrieve deleted items from Outlook folders. Can access password-protected .pst files. Can also repair and restore Outlook Express data. | |
Support tool used to create a truncated copy of a .pst file which allows some recovery when the file size has reached over 2 gig. The copy does not have all the original data because the tool cuts a user defined amount of data from the file. See KB 296088. | |
BackOffice Resource Kit utility that can identify which mailboxes contain messages meeting certain criteria, such as a virus-infected file attachment. See XADM How to Find Mailboxes That Contain a Specific Message for more information. | |
Provides warnings and restrictions to prevent a user from exceeding the 2gb storage limit for a Personal Folders .pst file. Can be configured to alert an administrator. | |
OutlookFix is an Outlook repair software tool for damaged, erased or large Outlook PST files. Restores Outlook files, will undelete emails and files, and lets you reduce the size of Outlook (Outlook 2gb limit fix) solving the common 2Gb size problem. | |
Outlook .NET pst/ost native parser. Pass the .pst or .ost file by header or extension, strip attachments, get all items (Appointments, Calendar, Folders, Email, Tasks, etc.), recover deleted or orphaned items. Allows you to continue processing if file is corrupt. Works with 97 - 2007 format, all encryption methods, and password protected files. Outlook is not required. Does not use MAPI or CDO. Version 4.20 | |
Use PstViewer Pro to view, search, print, reply to, and export email stored in your Outlook .PST files. Just start PstViewer Pro and select the folder with your .pst files. Click on the .PST file to reveal folders, emails, and file attachments. Renders Outlook emails in their original html, rich text or text formatting. Export your emails to different formats, including PDF, HTML, MHT, CSV, JPG and more. Includes reply, and search capabilities. Can also open .eml and .msg files. Outlook not required. | |
Recovery for Outlook repairs corrupted Outlook mailboxes (.pst). The program also supports Exchange Offline Storage Files (.ost). Supported Outlook versions: 2007, 2003, 2002, 2000, 98 and 97 | |
Recover data from Outlook pst files. Recover Exchange ost files and/or convert them into Microsoft Outlook pst files. Export data from pst files into eml and vcf files. | |
Exchange OST to PST email conversion tool to convert OST file to PST file. Convert working or unusable OST file to into PST file. Use it to migrates all Outlook items from Exchange Offline Storage (.OST) file to Personal Storage File (.PST). Software converts and repairs the offline storage file (ost) to personal storage (pst) file so that it can be easily accessed with Outlook. Other saving options include .EML and .MSG where former is accessible with Outlook Express and latter with Outlook. If the ost file gets corrupt or damaged, OST to PST functions as ost recovery software. | |
PST File Splitter reduces the size of a large PST file by splitting it into small parts and helps in avoiding the PST corruption situations. Stellar Phoenix PST File Splitter splits large PST file on the basis of email Id, date and folder size and keep the original PST file intact. It allows to create batch files for automating splitting process and also provides the log report of every operation. PST file splitter is available with both single user and corporate versions and efficiently works with Outlook 2010, 2007, 2003, 2002 and 2000. | |





