How to Compact OST File: A Step-by-Step Guide?

An OST file (or Offline Storage Table) is a copy of Outlook users’ data, such as emails, contacts, calendars, etc., stored on their computer. Users can easily access their important emails, contacts and other data even when they are offline. Throughout time, the size of an OST file grows that slows down Outlook’s performance and consumes unnecessary storage. Fortunately, users can compact OST files to avoid such issues and work smoothly. Also, this process generally helps in removing unused or unneeded items and prevents OST file size issues.

Outlook 2010 and above versions allow users to store up to 50 GB of data in an OST file. On the other hand, this file size limit is 2GB if users are using older versions, including Outlook 2002 and below versions. Users looking to compact an OST file should first understand this process’ benefits and then discover ways to accomplish it.

Advantages of compacting large OST files

Users have various benefits of compacting or reducing OST file size in Outlook email clients. A few common advantages from many are listed below.

  • Outlook takes no load when opening smaller OST files and operates faster.
  • Users must compress OST files constantly to keep sufficient storage on their system.
  • Moreover, the large OST file has a high chance of corruption. So, users should shrink or compress the OST file to protect data from future mishaps.

Users can compact OST files regularly to get such benefits and work on Outlook without facing a single issue. In addition, users will have more benefits of reducing OST file size from larger ones. Now, we will be discussing the simple ways to shrink OST files and prevent data from unwanted issues due to a large-sized OST file.

What are the ways to compress and compact OST files?

Various ways are available to compact OST files effectively. These solutions will simply help users to reduce OST file size and make them work smoothly. Let us now start discussing the simple solutions without taking more time.

1. Compacting OST file size using the Outlook’s ‘Compact Now’ option

Users can easily compact OST files manually using the Compact Now option available in the Microsoft Outlook email client. It compresses the overall size of the Outlook Storage Table (OST) and smoother the business’ workflow. The following steps will help users in reducing Outlook Offline Storage Table (OST).

  • Open Microsoft Outlook and select the File tab.
  • Then, tap the Account Settings drop-down and choose the Account Settings option.
  • From the Account Settings page, click the Data Files tab and select the OST file you want to compact.
  • After that, select the Data Files tab and click the Advanced option.
  • Next, look for the Outlook Data File Settings option and press on it.
  • Click Compact Now to compact the OST file and hit the OK button.

Use the above steps to implement the Compact Now option of Outlook to compact OST files manually. In addition, this solution effectively reduces OST file size; but has a few limitations when processing OST files.

Limitations:

  • This solution needs enough space in the drive. If users do not have sufficient space, the process can fail.
  • If the compacting task is interrupted, users may end up corrupting their OST file data.
  • Users need to reduce OST file size regularly to get completely out of large-size OST file issues. Hence, this process can become time-consuming as it involves several manual steps that users need to perform periodically.

2. Compressing OST file through Outlook Mailbox Cleanup option

Removing mailbox items can also help in compressing OST file size. Here, we will reduce the OST size by utilizing the Microsoft Outlook Mailbox Cleanup feature; let’s understand the steps.

  • In Outlook, go to File, Info tab and click the Cleanup tools drop-down.
  • Next, you need to select the Mailbox Cleanup option to continue.
  • Now, click the View Mailbox Size option from the Mailbox Cleanup window. (View OST file size or view mailbox size on the server.)
  • Choose any from the Find items older than or find items larger than options to compact the OST file.
  • As per your option choice, enter the number of days of which data you want to remove or set a certain size of the items to move larger ones from the OST file.
  • Also, you can directly empty or delete all items permanently in one click if you don’t need them.

We would urge users to first read its drawbacks before compacting up their OST file using this solution. These limitations can interrupt the whole process of compressing OST files, so better to know earlier.

Limitations:

  • This method may not significantly reduce the size of the OST file when the file stores large attachments or other items.
  • Moreover, it’s not a quick solution; it may consume too much time, especially when the OST file has a larger size.
  • All Outlook versions do not support the advanced compacting option for reducing OST file size. So, it might be not useful for all Outlook users.

A professional tool to compact OST files without any limitations

Users have to face several problems when compacting OST files using manual solutions. Hence, users rely on professional third-party software to compact the OST file effectively and smoothly. The Shoviv PST or OST Compact Tool is the professional’s choice to shrink or compress OST files with no restrictions. This software allows users to process various Outlook data files in one go and retains folder hierarchy perfectly. Users can easily add oversized PST or OST files in this software to reduce their sizes.

Moreover, users will be able to manage both kinds of PSTs, including Unicode or ANSI. It also offers the Exclude Duplicate Items option, which users can use to remove duplicate items during the OST or PST file compressing process. Users can archive attachments or remove attachments and then move them to a folder to compact OST or PST files.

Closing Words

Large-sized OST files can lead to data corruption situations. Therefore, using a perfect solution to reduce OST file size and avoid oversized OST file errors. For this, we introduced three solutions, two are manual. The manual solutions are easy to use but come with a lot of limitations. So, if you want to compact the OST file without restrictions, you must choose the Shoviv PST Compact and Compress Tool. The free evaluation version of this software is also available for the users. You can download it and freely process 50 items per folder to know its functionality and capability better.

Vishesh Kumar
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