How to Reduce Outlook Mailbox Size?

Updated on August 23, 2024 by Savita Sharma

Having an upper size limit is obvious for any application or file type, and Outlook is no exception. Over the years, Outlook mailbox sizes become oversized after excessive use of the Outlook email client, directly affecting the performance. When your Outlook mailbox size reaches its upper limit, you may face problems sending or receiving emails and other tasks. This blog provides simple workarounds to reduce Outlook mailbox size and a detailed guide.

Issues You May Face with Increased Outlook Mailbox Size

If your Outlook mailbox size reaches its limit, you may face many problems discussed below.

  • Your Outlook application productivity/working may slow down.
  • Corruption chances will increase in Outlook PST files.
  • You may face difficulty sending or receiving a new message.
  • High chances of losing your data due to increased Outlook mailbox size.

Let’s Explore the Workarounds to Reduce Outlook Mailbox Size:

1. Use Outlook Mailbox Cleanup Tool

  1. Open the Outlook Application and then Files>>Info>>Tools.
  2. Here, make a selection for the "Mailbox Cleanup Tool".
    Steps to Reduce Outlook Mailbox size
  3. Now, you can see various options like filtering older emails and large items, etc. Now, you can empty the items as per the need.
  4. You can also "Auto Archive" the emails.

2. Delete large Outlook emails and attachments

  1. For this, open Outlook, and under the folder section, go with the 'Search Folders'.
  2. Go to the 'organizing mail', go with the 'Large Mail'>>Choose.
  3. Provide a size to filter large mail. Enter a size against 'Show mail greater than'.
  4. Finally, click on the OK, and a new folder will be created with the large emails.

Now, you can free up space by removing this folder.

3. Use the Compact Now Feature

  1. Open Outlook and go to the File tab.
  2. Select Outlook and Account Settings.
  3. Click on the Data Files tab, select the PST file, and finally click on Compact Now.
    Reduce or compact PST file size manually

4. Reduce Outlook Mailbox Size Using Archive Older Messages

  1. Open Outlook Application.
  2. Follow: Files>>Options>>Advanced.
  3. Go for the Auto Archive Settings under the AutoArchive Panel.
    Effective Strategies to Reduce Your Outlook Mailbox Size
  4. Moreover, you can schedule the days for the Auto-Archive.
    Manage and Shrink Your Outlook Mailbox

5. Use Professional tool to Split PST File Size

To get rid of large PST files, the best option is to split the PST files. Splitting PST helps you manage the data and resolve issues due to oversizing. It is the practice used by most professionals to reduce Outlook mailbox size.

How Do Professionals Split PST Files?

No professional wants to deal with the manual way's complications, needing a one-stop solution. For the same, Regain Software has developed advanced software that can easily manage the size of Outlook PST files. Using this, you can easily maintain the size of the PST File and resolve the issues due to the oversized PST files. Let's explore some of its prominent features:

  • Regain PST Splitter can add PST files of any size without restricting the size; there is no size limit.
  • This tool offers three user-centric options to split the PST file: Split PST File by Size, Filtering by Message Date Criteria, and Split by the message content. I,e. From, Subject, To, etc.
  • It works for both types of PST files: Unicode and ANSI.
  • This utility professionally maintains the data integrity, including the meta-properties and other properties.
  • Similarly, the folder hierarchy remains intact.
  • It is compatible with all the versions of Windows Operating Systems.

Simple Steps to Split PST Files to Reduce Outlook Mailbox Size:

  1. Firstly, install and open the Regain PST Splitter Tool.
  2. Now, browse the PST file that you want to split.
    Regain PST Splitter for reducing Outlook mailbox size
  3. Here, you will have a preview of the content within the PST file.
    Add PST files
  4. Now, you will get three options to split the PST file: Split by Size, Split by Dates, and Split by Message Contain like CC, BCC, From To, and Subject.
    Select PST Size
  5. Finally, browse the destination path where the new resultant PST file will be saved.
    select destination
  6. Process to split the PST file will start.
    Successfully reduce Outlook mailbox size

Final Words:

An oversized mailbox size always creates issues and adversely affects Outlook's performance. If you face the same problem and have tried all the manual workarounds, consider splitting PST files. For the same, Regain PST Splitter is a one-stop solution recommended by many professionals. Using this, users can add any large-sized PST file and split it into the required size. A free trial version of this software is also available to download.

Frequently Asked Questions

Q 1. After what limit should we reduce the Outlook mailbox size?

Ans. Microsoft has recommended an upper size limit of 50 GB for the PST files. If you have reached or crossed this limit, then you should reduce Outlook mailbox size.

Q 2. If I enable Auto-Archive for 14 days, do I need to renew these settings after any time interval?

Ans. The Auto-Archive setting will remain the same as you have mentioned in the auto-archive settings. There is no need to renew afterward as there is no such restriction or provision.

Q 3. Is it possible to split the PST files on a 'Subject' basis?

Ans. You can split PST files on the 'Subject' basis using the Regain PST Splitter option. Moreover, you can split on the size and date range basis.

Q 4. Will I get the same folder hierarchy after splitting the PST using the Regain PST Splitter?

Ans. The resultant PST files will have the same folder hierarchy as the older ones. The tool will only split it according to the option you have chosen. By splitting, you can easily reduce Outlook mailbox size.