Top 5 Methods to Compact Large PST File

Many times Outlook PST file becomes over-sized with time and may get corrupt. To get rid of this, we have to reduce the size of the file by compacting it. So,top 5 methods of compacting the PST are mentioned, which would be helpful to user.

MS Outlook is an email client that stores all the data of a user in a database like file, which is known as Personal Folder file having PST extension. All the mailbox data of a user (including his emails, contacts, and notes) is stored in a PST file that is located on the hard drive of the user's local system. With time, as the number of emails, contacts, etc. increase in Outlook mailbox, the size of Outlook PST file also gets bigger and after a time, (depending upon your usage) you may find that your PST file is bloating.

Earlier Outlook versions, Outlook 2002 and earlier, use ANSI format for PST file, thus can store data up to 2GB. On the contrary, the later versions such as Outlook 2003, 2007 use UNICODE format and hence, have 20GB PST file size limit. Since large PST file causes performance deterioration in Outlook as well as gets corrupt when crosses its predefined size limit, thus it is suggested to keep the size of PST file small. However, the problem of PST corruption is seen often in earlier Outlook versions like Outlook 2002 as 2GB is a small limit, but later versions (Outlook 2003, 2007, 2010, and 2013) as well lose their speed, as PST gets bigger in size.

In order to optimize the performance of Outlook and avoid PST corruption and data loss, it is suggested to use some efficient measures to clean PST. Mentioned below are top five ways to keep the size of PST file small:

• Delete Unused Items: One of the easiest ways for keeping PST small is deletion of unused items from Outlook mailbox. If possible, empty the 'Deleted Items' folder on regular basis as well.

• Archive Old Items: If you have some old yet important mailbox items that you cannot remove as well as keeping them increasing the size of PST, then sending them to an archive PST file can reduce the size of your main PST file. Therefore, send all the old and rarely used mailbox items to the archive PST file.

• Split Large PST File into Multiple Smaller PST Files: Since your Outlook can handle more than one PST files, thus you can keep more than one PST files of small sizes than one large PST. Therefore, splitting a large PST file into multiple smaller PSTs can be a way to keep the size of PST file smaller.

• Use 'Compact Now' Feature of Outlook: Outlook provides you a feature to compact your large PST file. You can compact your PST file through 'Compact Now' feature of the software manually. Use the following steps for compacting your large PST file manually:
• Open Outlook and from the menu, select 'File >> Data File Management'.
• Highlight your desired PST file.
• Click 'Settings', and further click 'Compact Now'.

However, if your PST file is large, then this process may take large amount of time. Additionally, this method may lead to data loss.

• Professional Tool to Compact PST: The best and the most efficient way to compact PST file is professional PST compaction utility. Reliable professional software of this category reduces the size of Outlook PST file without causing data loss and without taking much time.

You can select any of the methods from the aforementioned ones for compaction of your large PST file.

Read How to recover deleted files from Microsoft Office Outlook 2003 and 2010


Guest Author: Russell Smith14 Oct 2013

In my case, i always try Stellar compact PST software to compress large PST file instantly.

Author: Jhon23 Oct 2013 Member Level: Bronze   Points : 2


I suggest you SysTools split PST software to compact you .pst files without losing any data.
The software split large .pst files by date, year, folder and by size and save them at secure location where ever you want.

Author: Jan Papst24 Mar 2014 Member Level: Bronze   Points : 0

To compact large sized PST files, try SysInfoTools PST Compress & Compact tool. This tool will safely remove all the unused and extra space from the PST files and make them compatible in size.

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