Office for Mac Issues

Fix Not Enough Memory or Disk Space Error During Word Mail Merge on Mac

Algirdas Jasaitis Sep 25, 2026 869 views

Question details

The user is unable to complete a Mail Merge in Microsoft Word using an Excel spreadsheet as the data source due to a memory or disk space error warning.

Product: Microsoft Word for Mac
Device & OS: macOS Sonoma
Scenario: Executing a document Mail Merge in Word utilizing an external Excel workbook for the data source.
Observed behavior: Word aborts the operation and displays a 'not enough memory or disk space' error, even after converting the data source to an older XLS format.

Before you start

Verify that your Mac has sufficient actual disk space available in System Settings, and make sure to save all your current progress in both Word and Excel before attempting these fixes.

Solution 1Recommended

Perform the Mail Merge via Word for the Web

Using the web-based version of Microsoft Word bypasses local application bugs and macOS memory allocation conflicts.

If the desktop application is falsely reporting a lack of storage or memory, migrating the task to the cloud environment is often the fastest and most reliable workaround.

Upload Files to OneDrive

Open your web browser, navigate to OneDrive, and upload both your Word main document and the Excel data source.

Open Word Online

Click on the uploaded Word document in OneDrive to open it in Word for the web.

Execute the Mail Merge

Navigate to the Mailings tab, select 'Start Mail Merge', and choose your uploaded Excel file as the recipient list to complete the process online.

Perform the Mail Merge via Word for the Web

Cloud Processing: Processing the merge online utilizes Microsoft's servers, completely avoiding your Mac's local memory and disk limitations.

Solution 2

Start Your Mac in Safe Mode

Booting your Mac into Safe Mode clears system caches and disables third-party extensions that might interfere with Word's memory management.

Solution 3

Recreate the Excel Data Source

Hidden formatting or corrupt metadata within the original Excel file can trigger false memory errors in Word.

WPS Office Mail Merge

Perform Mail Merge Seamlessly with WPS Office

If Microsoft Word continues to struggle with false memory or disk space errors on your Mac, WPS Office provides a lightweight, powerful alternative to seamlessly execute Mail Merge tasks without overwhelming your system.

1. Open Your Document: Launch WPS Writer and open your primary document template.
2. Access Mail Merge: Navigate to the 'References' tab on the top ribbon and click on 'Mail Merge'.
3. Link Data Source: Click 'Open Data Source' and select your existing Excel (.xlsx or .xls) spreadsheet containing the recipient details.
4. Insert Merge Fields: Place your cursor where you need personalized data and click 'Insert Merge Field' to map your Excel columns.
5. Merge to New Document: Click 'Merge to Different New Document' to generate your personalized files instantly.

Lightweight application footprint prevents memory overload and disk space errorsFully compatible with Microsoft Word (.docx) and Excel (.xlsx) formatsIntuitive Mail Merge wizard built directly into WPS Writer for easy processing

microsoft office alternative - wps office

Frequently Asked Questions

Why does Word say there is not enough memory or disk space when I have plenty available?

This is often a false positive error caused by corrupted Microsoft Office preferences, hidden formatting issues in the linked Excel source, or memory allocation bugs within macOS Sonoma, rather than an actual lack of storage.

Does saving my Excel file in an older format help fix Mail Merge errors?

While converting from .xlsx to the older .xls format is sometimes recommended to reset the file's structure, it frequently fails to resolve deep-seated file corruption. Recreating the file by pasting the raw values into a new workbook is usually a more effective solution.

How do I check my actual available disk space on macOS Sonoma?

Click the Apple logo in the top-left corner, select 'System Settings', click on 'General' in the sidebar, and then click 'Storage' on the right. This will show you exactly how much actual disk space is available on your drive.

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