Exchange Connection Problems

How to Separate Outlook Email and Attachment Storage Usage

Guest Writer Oct 1, 2026 868 views

Question details

The user wants to know if it is possible to view separate storage usage totals for email messages and file attachments in a Microsoft 365 Outlook mailbox.

How to Separate Outlook Email and Attachment Storage Usage

Product: Microsoft Outlook
Device & OS: not provided
Scenario: Monitoring detailed mailbox storage consumption to manage space and apply limits effectively.
Observed behavior: Outlook and the Exchange Admin Center only report a combined storage usage total for emails and attachments, providing no clear separation between the two data types.

Before you start

Before attempting to check advanced mailbox statistics, ensure you have the necessary administrator permissions in Microsoft 365 and have the Exchange Online PowerShell module installed on your system.

Solution 1Recommended

Review Folder Sizes Using Exchange PowerShell

Since the Exchange Admin Center doesn't natively separate attachments from emails, administrators can use PowerShell to get a detailed breakdown of folder sizes as a workaround.

Microsoft Outlook and the Exchange admin center generally report combined mailbox usage rather than separate email-only and attachment-only totals. Features like 'Manage Mailbox Size Restrictions' only set limits but do not provide granular breakdowns.

To get more insight into what is consuming space, administrators can run the Get-MailboxFolderStatistics command in Exchange PowerShell. While this still does not provide a perfect attachment-only breakdown, it helps identify the specific folders taking up the most storage.

Open Exchange PowerShell

Launch PowerShell on your computer as an Administrator and connect to your Exchange Online environment using the appropriate connection module.

Run Folder Statistics Command

Type the command 'Get-MailboxFolderStatistics -Identity <username> -FolderName Inbox' (replace <username> with the actual user ID) and press Enter to retrieve detailed size metrics for the inbox.

Review Mailbox Usage

Analyze the output to identify which folders are consuming the most storage space. You can modify the command to check the entire mailbox instead of just the Inbox folder.

Review Folder Sizes Using Exchange PowerShell

Submit a Feature Request: Because exact attachment-only reporting is not a supported feature, it is highly recommended to submit this request to Microsoft through the Outlook Feedback portal or by clicking Help > Feedback within the Outlook application.

Free Microsoft Office alternative

Manage Your Documents Better with WPS Office

While managing mailbox storage in Outlook can be challenging, managing your documents doesn't have to be. WPS Office is a free, lightweight, and highly compatible Office suite that helps you create, edit, and compress your Word, Excel, and PDF files efficiently, ensuring your email attachments take up less space.

1. Download and Install WPS Office: Visit the official WPS website to download the free installer. Run the application and follow the on-screen instructions to complete the setup.
2. Open and Edit Your Documents: Launch WPS Office and open your existing Word, Excel, or PowerPoint files directly. The software automatically recognizes standard Microsoft Office formats.
3. Compress Files Before Emailing: Use the built-in PDF tools or document optimization features in WPS Office to reduce file sizes before attaching them in Outlook to save mailbox storage.

Fully compatible with Microsoft Office formats like .docx, .xlsx, and .pptx.Built-in PDF tools to easily compress files and reduce email attachment sizes.Lightweight design ensures fast loading and minimal local storage consumption.Familiar user interface requires no learning curve, allowing for a seamless migration.

microsoft office alternative - wps office

Frequently Asked Questions

Can regular users see their attachment size breakdown in Outlook?

No, the Outlook application only shows the total mailbox storage used. Regular users cannot separate the storage data used by text emails versus file attachments within the standard interface.

Does deleting emails with large attachments free up mailbox space?

Yes. Since emails and attachments share the same mailbox storage quota, deleting messages containing large attachments (and subsequently clearing the Deleted Items folder) is the most effective way to free up space.

How can I quickly find large attachments in Outlook to delete?

In the Outlook desktop app, you can use the Search bar and select the 'Has Attachments' filter. Once the results appear, sort the emails by 'Size' to quickly identify and delete the largest files in your mailbox.

Outlook & Email Problems