How Do I Reduce the Size of Mailbox and Outlook Data File

Before proceeding with the multiple methods, let’s first discuss why there is a need to do so.

Why is there a Need to Reduce the Size of Outlook Mailbox?

There are multiple problems Outlook users need to face due to oversized mailboxes. Some of the major issues have been listed below such as:-

• The productivity and performance of an Outlook application degrades.
• It hampers the flow of communication via sending or receiving new email messages.
• Redundant Outlook applications that prevent access to the service
• Oversized data in an Outlook PST file increases the possibility of corruption.
• Loss of data can occur due to a rise in the level of corruption in the PST file.

How to Reduce Outlook Mailbox Size.

In order to reduce Outlook data file size, we have a few simple methods available. Such as:-

Method 01: By using Mailbox Cleanup Utilities

You can control and regulate the size of your mailbox and Outlook data files using the Mailbox Cleanup option in Outlook. You can use this utility to reduce the size of the mailbox and Outlook data file by permanently removing deleted mail items and duplicate or alternate versions of mail items from your mailbox and Outlook PST file. Steps such as:-

• In Outlook, navigate to File > Cleanup Tools and click “Mailbox Cleanup”.
• To view mailbox size, click the “View Mailbox Size” button. To reduce the mailbox size and PST file size, hit the “Empty” button.
• The Mailbox Cleanup dialog box will close. Open it again via Cleanup Tools > Mailbox Cleanup, and this time hit the “Delete” button.
• Hit “Yes” to confirm.

Method 02: Backup/Archive and delete older or larger PST File Messages

In case the mailbox size is full, you can reduce the size and empty your Mailbox by deleting old or large emails that you don’t require more from your Mailbox or PST Outlook data file.

You can also avail local backup/archive old emails or messages with large attachments to another local PST file and delete them from your default PST or Mailbox. It will reduce the Mailbox .pst file size and allow you to access the archive emails from the local PST file. The steps such as:-

• Run an Outlook, go to File> Info> Cleanup Tools> Archive.
• Choose the folders you want to archive the mail items and select the date in Archive items older than:
• Click “Browse” to select a location where the mail items will be saved.
• Hit “OK”. It will start archiving emails and mail items older than the selected date, which will significantly reduce the Outlook mailbox size (.pst).

Method 03: Save Attachments outside the Mailbox

Find and delete the large messages if you don’t require them anymore, or save the attachments on a local drive or Cloud and delete them from the messages to reduce the mailbox (.pst) size. The steps are as follows:-

• Run an Outlook, click on the filter, and Select Size to list emails based on size.
• Choose the Largest to list emails in descending order.
• Open the large emails and save all the attachments on the local drive.
• After saving all the attachments, you may delete the message or keep the message but delete the attachments.
• To delete attachments, right-click on the attachment and select “Remove Attachment”.

Hence, It will remove the attachments and reduce the mailbox(.pst) Size.

Method 04: Compress the Size of an Outlook Data File (PST)

Outlook also provides a feature to compress or compact Outlook PST files to remove whitespace and reduce the mailbox size. The steps are as follows:-

• Run an Outlook and go to File> Account Settings > Account Settings.
• Click “Data Files” and choose the PST file from the list
• Hit Settings > Advanced and then click “Outlook Data File Settings…”
• Click Compact Now.

At last, it removes whitespace and reduces the PST file size.

Note: The above-mentioned few of the manual methods are easy to perform, but they require basic technical knowledge to implement the whole procedure smoothly. However, there can be chances of data loss in case a single step is missed in between. Due to these drawbacks of the manual method to reduce the size of the mailbox and Outlook Data File, we suggest going for a more appropriate and advanced approach, which is using a third-party Tool. Let’s move further and discuss this software in more detail.

Method 05: Using the Advanced PST Compact Tool to Reduce Outlook Data File Size

PST Compact Tool is the best utility to reduce the size of an Outlook mailbox or to compress large-size PST files with high precision. Additionally, it possesses several inbuilt features with it. It is compatible with all Windows operating systems, including Windows 11.

Let’s move towards the step-by-step guidelines of this software:

1. Download and Run the tool on your Device.
2. Choose the Single File option and hit the Next button.
3. Further, you will get an option to Select File, browse the PST file you want to compress, and click on the Open button. Further, hit Next.
4. After this, you can view the tree structure containing all the mailbox folders of your PST files. Select the folders you want, and additionally, you can preview the email data along with their attachment files. Hit the Next button.
5. Choose the Compression Option Panel. Here, we have selected Compress All Attachments in New PST File to continue the work. Additionally, opt for the in-built features as per the requirement.
6. Further, Assign a location in the Path to Save option for the newly generated compressed File. At last, hit on the Start Compression button to initiate the compression process.

Conclusion

Oversized Mailbox can trouble an Outlook user in multiple ways. However, we have provided some manual tricks. Additionally, we have also suggested third-party software, which provides a direct solution to reduce the size of Mailbox and Outlook data files to overcome such issues properly. The free demo version is also available online to check the efficiency of this software.

Frequently Asked Questions