You may need to see the size of emails directly in your inbox to manage your mailbox storage. Outlook does not display file size in the default message list view. This article explains how to add the Size column to your main message list. You will learn the steps to customize the view for any Outlook folder.
Key Takeaways: Add Email Size to Your Outlook View
- View > View Settings > Columns: Opens the dialog to add, remove, and reorder columns in your current Outlook folder view.
- Size field: Displays the total size of each email item, including attachments, in kilobytes or megabytes.
- Apply Changes to This Folder: Saves the column layout only for the folder you are currently viewing, not all mailboxes.
Understanding Outlook Columns and Views
Outlook uses a system of views and columns to organize information in your message list. The default view for your Inbox shows common fields like From, Subject, and Received. The Size field is available but not displayed by default. You can customize this view for any folder, like your Sent Items or a custom search folder.
Changes you make to columns apply only to the specific folder you are modifying. If you want the Size column in both your Inbox and Sent Items, you must configure each folder separately. Outlook for Microsoft 365, Outlook 2021, and Outlook 2019 all use the same method for this task.
Column Width and Data Format
The Size column shows data in a compact format. Small emails display in kilobytes, like “12 KB”. Larger emails with attachments show in megabytes, like “2.3 MB”. You can adjust the column width by dragging its border in the message list header. A wider column may show the full number without truncation.
Steps to Add the Size Column in Outlook
Follow these steps to add the email size to your message list columns. This process works for the main Mail module folders.
- Navigate to the desired folder
Open Outlook and click on the mail folder where you want to see email sizes, such as your Inbox. - Open the View Settings dialog
Click the View tab on the ribbon. In the Current View group, click View Settings. - Access the Columns menu
In the Advanced View Settings dialog box, click the Columns… button. This opens the Show Columns dialog. - Add the Size field
In the Show Columns dialog, scroll down the list of available columns on the left. Select Size from the list. Click the Add -> button to move it to the right-hand “Show these columns in this order” list. - Position the new column
With Size selected in the right-hand list, use the Move Up or Move Down buttons to place it where you want it to appear in your message list. A common position is after the Subject column. - Apply and save the changes
Click OK to close the Show Columns dialog. Click OK again to close the Advanced View Settings dialog. The Size column will now appear in your message list.
Using the Right-Click Method on the Column Header
A faster method exists for adding common columns. Right-click on any column header in your message list, like the “From” or “Subject” header. Select Field Chooser from the context menu. In the Field Chooser window, select All Mail fields from the dropdown list. Find and drag the Size field from the list directly onto your column headers. Drop it where you want the column to appear.
Common Mistakes and Limitations
Size Column Shows Zero or Blank Values
If the Size column is empty, you might be viewing a folder in a different module. Ensure you are in the Mail module, not Calendar or Tasks. The column may also show zero for very new emails that have not been fully processed by Outlook. Try switching to another folder and back, or restart Outlook.
Changes Do Not Apply to Other Folders
Column layout is per-folder by design. To apply a similar layout to another folder, you must repeat the steps. You cannot copy a view from your Inbox to your Sent Items through the standard column menu. For that, you would need to create and apply a custom view from the View tab.
Column Disappears After Restarting Outlook
If your Size column vanishes, your view may have been reset. This can happen if Outlook crashes or if an update changes settings. To prevent this, after customizing your columns, consider saving the view. On the View tab, click Change View and then Save Current View as a New View. Give it a name so you can re-apply it later.
Default Columns vs. Customized Columns
| Item | Default Column Set | Customized with Size Column |
|---|---|---|
| Columns Displayed | From, Subject, Received, Categories, Flag | From, Subject, Size, Received, plus any others added |
| Storage Management | Must open each email to see its size via File > Properties | Total email size visible at a glance for sorting |
| Application Scope | Consistent default across all new mail folders | Settings are specific to each individual folder you modify |
| Sorting Capability | Can sort by date, sender, or subject | Can also sort by size to find largest emails quickly |
| Setup Required | None, applied automatically | Manual configuration needed per folder |
You can now monitor your mailbox size directly from the main message list. Use the Size column to sort and find emails with large attachments. For more control, explore creating custom search folders for items over a specific size. An advanced tip is to combine the Size column with the “Arranged By: Size” right-click option on the column header for instant grouping.