Why does Outlook keep showing "Out of Memory or System Resources" when opening emails?

arjunmehta — Tue, 02 Jun 2026 06:14:49 GMT

Microsoft Outlook may display the error message “Out of Memory or System Resources” even on computers with plenty of RAM. This issue usually occurs when Outlook cannot efficiently access the resources it needs to open emails, calendars, or other mailbox items.

One common reason is an oversized mailbox or PST/OST file. Large data files require more resources to process, which can cause Outlook to slow down or generate memory-related errors. Corrupted Outlook data files can also trigger this problem, especially when Outlook attempts to read damaged email data.

Another possible cause is conflicting or faulty add-ins. Third-party add-ins often consume system resources and may interfere with Outlook’s normal operations. Running an outdated version of Outlook can also lead to compatibility and performance issues.

To fix the problem, start by closing unnecessary applications running in the background. Next, reduce mailbox size by deleting or archiving old emails and large attachments. Disabling unused add-ins through Outlook Options can also improve performance. Additionally, ensure that Microsoft Outlook and Office are fully updated.

If the error persists, repair your Outlook data files using the Inbox Repair Tool (ScanPST). In cases where the OST file is corrupted or inaccessible, a professional Aryson OST recovery tool solution may help restore mailbox data.

By maintaining a manageable mailbox, keeping Outlook updated, and repairing damaged files when necessary, you can prevent most “Out of Memory or System Resources” errors and enjoy a smoother Outlook experience.

topic Why does Outlook keep showing "Out of Memory or System Resources" when opening emails? in Discussions

Why does Outlook keep showing "Out of Memory or System Resources" when opening emails?